It is not possible to edit non-synced plans that were created for you by your team lead or another user with Manage Plans permission.
Synced plans can be updated if you have permission to edit the synced fields in Jira.
Planning work is often done by your resource manager or team lead, but you can also plan your own time in Tempo Planner. For example, you can plan your vacation or personal time off, plan your recurring meetings, and also possibly manage your plans on a weekly basis.
When you create plans ahead of time in the Resource Planning view, it's easy for resource managers and your team lead to know when you're not available for working on projects. This also helps them make sure that projects are properly staffed during your time off.
There are different ways that you can plan time:
If Sync Plans with Jira Issues is enabled, simply create a new issue and fill in the synced fields used for plan start date, plan end date, total planned time, and assignee. (If you’re not sure what these fields are, speak with your Team Lead or Jira Administrator.
From the Resource Planning view: use the Weeks view for planning ahead (such as for vacation), or the Days view for adjusting plans for the current week.
From the Jira issue view to create a plan directly for that issue - see below.
From the My Work Calendar if you have Tempo Timesheets installed - see Planning Your Time.