Python script not compatible with the new youtube API -quick job

I've got a youtube script that batch analyzes youtube playlists and fetches the videos that fit my criteria and then putting them in a brand new playlist (simple automation tool). Anyway, it has stopped working a few months ago, probably because youtube changed it's API policy and I need to integrate it, so I can use it once again. It's probably a matter of creating new API/Oauth credentials and editing code a bit so it's compatible, but somehow can't figure out how to do it myself and need help.

I use windows and command line to run it.

Link to the script: https://pastebin.com/mAHQVmm5