Access to API for GPT4 Error "Not Found"

I see many discussion here but I cannot figure out what to do. I have purchased access to GPT4 (20$/month) about a month ago. I generated api key. When I try to use the api key with Model = Model.GPT4 I get an error “Error at chat/completions with HTTP status code: NotFound.”. It work with model ChatGPTTurbo I get answer but it is not good enough (I get teh right results if I use the chat in the conversational page.
I see in te documents that I need to purchase pre-paid of 1$ but I don’t know where to do it as I don’t have such option in teh billing page

You have purchased access to ChatGPT Plus which is a product that uses GPT-4. So you have enabled the usage of GPT-4 within ChatGPT.

That does not give you access to GPT-4 on OpenAI API.

Please check here which models are available:

Also I recommend playing around with GPT-3.5 as well. It is not really that bad. I have access to GPT-4 but barely use it, cause GPT-3.5 can do most and it is cheaper.

Thanks a lot. I will see whet I can do with 3.5. I tried the link you sent and there are only 3.5 models available. The issue is that I don’t know how to apply for the API for GPT4. I don’t see any form where I can ask for it.

I think you are searching for this.

Also keep in mind that you are charged for api usage based on tokens.