How to make an API call to a custom GPT model?

Not a bad way of looking at it, essentially there are 3 levels of “complexity” and with that control, the first is GPTs which require no coding skills at the basic level, although making use of API’s and tools can get interesting, then there is assistants which you have to create the functions for yourself and handle the calling and returning of data, and then there is the root API where you control everything manually.