Jira Service Management agents/users need a license to log time

This article is for Tempo for Cloud and Data Center

Users need to be a Service Management agent to log work on a JSM ticket.
Users who are not JSM-agents can write internal comments on JSM issues, but cannot create any worklogs. This is due to JSM permissions overriding the Jira Project permissions.
To check if the set Jira Project permissions are overwridden by JSM, the Jira permission helper can be used (JIRA Administration, System, Permission helper)

Cloud - Overview of Jira Cloud permissions

Data Center - Permissions Overview

It would be better to contact Atlassian Support directly if you have any further questions.

Also, below are related Atlassian tickets:

Cloud - JSDCLOUD-1641
Data Center - JSDSERVER-1641