They require, in the harshest of cases, (1) a full-length video of you actually playing the session, with input methods visible in frame, hosted on a publicly accessible site such as YT or Twitch, (2) game audio must be audible and undistorted, and (3) hardware input tracking software logs - I'm not sure what the application they use is called but you can easily find out. There might be other requirements I forget, you can probably google it easily.
With these things required, the community polices itself. Staying ahead of these things in code is completely wasted effort that could be spent on positive coding, which grows the community and therefore reinforces the self-policing.
These requirements might seem harsh and alienating, but I'd just say "get over it, if you want to compete, these are the rules."