Crackers alter the original amtlib.dll or Photoshop.exe files, patch the license check functions, or use keygen tools. Sometimes, they include a fake activation server. The goal is to make Photoshop think it is licensed without a valid subscription.
Pro tips from preservationists:
Installing the pre-activated version of Adobe Photoshop 2021 involves a straightforward process: Adobe Photoshop 2021 v22.5.1.441 Pre-Activated