Dowload the Codex UI at
- log in with your OpenAI (I assume you're on a mac here)
- create a new empty folder somewhere and then with Codex open a project/thread in there
- set it to Gpt-5.3-Codex (maybe Extra High)
- (during runtime you might progressively want to say Yes to various permissions - you won't go far apart from downloading python stuff if you don't have it)
- start chatting with it a bit, then dump in the following longer prompt at once: