To open your timesheet as a team member, navigate to Team > Timesheet in the left sidebar and click on My Timesheet in the top navigation. Don’t forget that you can have an updated timesheet by simply tracking regularly your time for every subtask.
To track your time, click on any day and select the time to be tracked. Confirm by clicking on OK and now click on the comment icon to assign the time tracking to an epic and team. You can also add a comment to each time tracking.