curl --location --request GET '/rest/api/3/configuration'
{"attachmentsEnabled":true,"issueLinkingEnabled":true,"subTasksEnabled":false,"timeTrackingConfiguration":{"defaultUnit":"day","timeFormat":"pretty","workingDaysPerWeek":5.0,"workingHoursPerDay":8.0},"timeTrackingEnabled":true,"unassignedIssuesAllowed":false,"votingEnabled":true,"watchingEnabled":true}