Only workspace administrators can add time for their team members from Detailed Reports page.
When clicking on the green Add time for team button, you’ll see a form familiar to the one appearing in the Manual Mode on the Timer page. The main difference is the new Select User field:
If you want to change the User on an existing time entry, click on the User’s name in the list and select a different one.
Please note that workspace administrators cannot add (or edit) time entries within private projects in which the workspace administrator is not a member.