1. Hold down option on startup.  
  2. At the next window enter in firmware password. 
  3. When the next window appears asking you to choose a network, press keys in this order. Option+command + R.  This will take you to update recovery mode. This could take up to 10 min.
  4. Choose "Re-Install Monterey"
  5. Reinstall Monterey. Do not erase HD.