You can continue to work on them. Just remember: as per the Canada Revenue Agency, they are currently shut down for its annual maintenance to prepare for the 2022 tax filing year, they remind you that Auto-Fill My Return (AFR) is not fully functional until March 15, 2023. You may be able to use the service by February 20th, 2023, but they still may not have all the slips online.
Thank you for your patience.