Switch to a backup site. The "123movies" ecosystem has dozens of cousins: LookMovie, Soap2Day (variants), Fbox, or Bflix. The methodology to fix them is identical to the steps above.
If the site is loading but broken or redirecting you to ads, try these steps: 12345movies fix
Navigating the Maze: A Guide to Fixing 123Movies and Its Clones Switch to a backup site