Use any model and any provider with the official OpenAI Codex Desktop App, without modifying its code, and continue to use the official models in parallel?

All in the title. The official OpenAI Codex Desktop App only accepts models that are from OpenAI and from a curated list. But there is a trick, you can make it think you are using the official OpenAI servers and models by just impersonating the model name and using another one. There is three things