update and fields. The fields that can be set in the issue or subtask are determined using the  Get create issue metadata. These are the same fields that appear on the issues' create screens. Note that the description, environment, and any textarea type custom fields (multi-line text fields) take Atlassian Document Format content. Single line custom fields (textfield) accept a string and don't handle Atlassian Document Format content.issueType must be set to a subtask issue type (use  Get create issue metadata to find subtask issue types).parent the must contain the ID or key of the parent issue.curl --location --request POST '/rest/api/3/issue/bulk' \
--header 'Content-Type: application/json' \
--data-raw '{
    "issueUpdates": [
        {
            "fields": {
                "assignee": {
                    "id": "5b109f2e9729b51b54dc274d"
                },
                "components": [
                    {
                        "id": "10000"
                    }
                ],
                "customfield_10000": "09/Jun/19",
                "customfield_20000": "06/Jul/19 3:25 PM",
                "customfield_30000": [
                    "10000",
                    "10002"
                ],
                "customfield_40000": {
                    "content": [
                        {
                            "content": [
                                {
                                    "text": "Occurs on all orders",
                                    "type": "text"
                                }
                            ],
                            "type": "paragraph"
                        }
                    ],
                    "type": "doc",
                    "version": 1
                },
                "customfield_50000": {
                    "content": [
                        {
                            "content": [
                                {
                                    "text": "Could impact day-to-day work.",
                                    "type": "text"
                                }
                            ],
                            "type": "paragraph"
                        }
                    ],
                    "type": "doc",
                    "version": 1
                },
                "customfield_60000": "jira-software-users",
                "customfield_70000": [
                    "jira-administrators",
                    "jira-software-users"
                ],
                "customfield_80000": {
                    "value": "red"
                },
                "description": {
                    "content": [
                        {
                            "content": [
                                {
                                    "text": "Order entry fails when selecting supplier.",
                                    "type": "text"
                                }
                            ],
                            "type": "paragraph"
                        }
                    ],
                    "type": "doc",
                    "version": 1
                },
                "duedate": "2011-03-11",
                "environment": {
                    "content": [
                        {
                            "content": [
                                {
                                    "text": "UAT",
                                    "type": "text"
                                }
                            ],
                            "type": "paragraph"
                        }
                    ],
                    "type": "doc",
                    "version": 1
                },
                "fixVersions": [
                    {
                        "id": "10001"
                    }
                ],
                "issuetype": {
                    "id": "10000"
                },
                "labels": [
                    "bugfix",
                    "blitz_test"
                ],
                "priority": {
                    "id": "20000"
                },
                "project": {
                    "id": "10000"
                },
                "reporter": {
                    "id": "5b10a2844c20165700ede21g"
                },
                "security": {
                    "id": "10000"
                },
                "summary": "Main order flow broken",
                "timetracking": {
                    "originalEstimate": "10",
                    "remainingEstimate": "5"
                },
                "versions": [
                    {
                        "id": "10000"
                    }
                ]
            },
            "update": {
                "worklog": [
                    {
                        "add": {
                            "started": "2019-07-05T11:05:00.000+0000",
                            "timeSpent": "60m"
                        }
                    }
                ]
            }
        },
        {
            "fields": {
                "assignee": {
                    "id": "5b109f2e9729b51b54dc274d"
                },
                "components": [
                    {
                        "id": "10000"
                    }
                ],
                "customfield_10000": "09/Jun/19",
                "customfield_20000": "06/Jul/19 3:25 PM",
                "customfield_30000": [
                    "10000",
                    "10002"
                ],
                "customfield_40000": {
                    "content": [
                        {
                            "content": [
                                {
                                    "text": "Occurs on all orders",
                                    "type": "text"
                                }
                            ],
                            "type": "paragraph"
                        }
                    ],
                    "type": "doc",
                    "version": 1
                },
                "customfield_50000": {
                    "content": [
                        {
                            "content": [
                                {
                                    "text": "Could impact day-to-day work.",
                                    "type": "text"
                                }
                            ],
                            "type": "paragraph"
                        }
                    ],
                    "type": "doc",
                    "version": 1
                },
                "customfield_60000": "jira-software-users",
                "customfield_70000": [
                    "jira-administrators",
                    "jira-software-users"
                ],
                "customfield_80000": {
                    "value": "red"
                },
                "description": {
                    "content": [
                        {
                            "content": [
                                {
                                    "text": "Order remains pending after approved.",
                                    "type": "text"
                                }
                            ],
                            "type": "paragraph"
                        }
                    ],
                    "type": "doc",
                    "version": 1
                },
                "duedate": "2019-04-16",
                "environment": {
                    "content": [
                        {
                            "content": [
                                {
                                    "text": "UAT",
                                    "type": "text"
                                }
                            ],
                            "type": "paragraph"
                        }
                    ],
                    "type": "doc",
                    "version": 1
                },
                "fixVersions": [
                    {
                        "id": "10001"
                    }
                ],
                "issuetype": {
                    "id": "10000"
                },
                "labels": [
                    "new_release"
                ],
                "priority": {
                    "id": "20000"
                },
                "project": {
                    "id": "1000"
                },
                "reporter": {
                    "id": "5b10a2844c20165700ede21g"
                },
                "security": {
                    "id": "10000"
                },
                "summary": "Order stuck in pending",
                "timetracking": {
                    "originalEstimate": "15",
                    "remainingEstimate": "5"
                },
                "versions": [
                    {
                        "id": "10000"
                    }
                ]
            },
            "update": {}
        }
    ]
}'{"issues":[{"id":"10000","key":"ED-24","self":"https://your-domain.atlassian.net/rest/api/3/issue/10000","transition":{"status":200,"errorCollection":{"errorMessages":[],"errors":{}}}},{"id":"10001","key":"ED-25","self":"https://your-domain.atlassian.net/rest/api/3/issue/10001"}],"errors":[]}