Way to stick it to em!
You can use this FOSS tool to automatically claim those games.
https://github.com/vogler/free-games-claimer
Some even work pretty well on Linux using the Heroic Launcher.
Does that still work? Last updated over a year ago and the free games are usually protected by some rather creative captchas.
Works for Prime and GOG. Epic sometimes works outside the docker container, but sometimes you still get a CAPTCHA still. There’s an active discussion for fixing Epic inside a docker container.