Until this April, Remote Pilots were required to take an FAA-designated 40 question "recurrent" exam at an FAA test center (and with the same fee as an initial exam) every 24 months to maintain their RPIC flight privileges. Under the new rule issued in April 2021:
After you complete the training, print out your “completion certificate” and keep it with your original (card) license. That printout is your only proof of your two year extension. You do not need to enter anything in your FAA pilot (IACRA) account. Your authority to fly as a Remote Pilot will continue to the last day of the 24th month from the month you did the course. When that time comes, repeat the above.
REGISTRATION PAGE FOR THE UAS RECURRENT COURSE AND EXAM. Credit: FAASafety.gov