Every 90 days, when requesting a mission, you'll need to confirm that you're current, have read and updates to the Handbook or Airport Procedures, and you're "FAA clear".

Then, click on the "Confirm Signup" button

NOTE: If the system won't let your request a mission, most likely, it's because your Medical or Flight Review (BFR) has expired. Visit your epilotlogs.com Pilot Profile and update your Medical and BFR dates. You should then be able to request a mission.