i use my APIKey, but Mathematica say "Your account is not active, please check your billing details on our website.", who can help me?
You can try
ServiceConnect["OpenAI", "New"]
but based on the error message it seems like you do not have billing setup correctly (as I mentioned earlier). Or you may have to prepay some $ into your account. Look at the billing page for details.
I have the API but don't know how to set up my API in Mathematica.
Have you set up a payment method on your OpenAI account?
Have you tried using the API key from a simple Python program or curl?
curl
