This post was split from the topic: Can I change the model to GPT-4 and utilize my plugins in Zapier's chatbot?
I partly solved the problem.
There are 2 ChatGPT apps - OpenAI and ChatGPT.
OpenAI doesn’t have GPT4
ChatGPT4 does have GPT4 but you can’t use it in the same way i.e. You can’t just enter a prompt. It seems to be more for things like chat bot conversations etc.
So, for my use case it seems like I am stuck with OpenAI and GPT3.5.