The API is completely separate from the online website and chat-bot know as ChatGPT.
You must add funds to you API account before you will be able to make calls to GPT-4.
The monthly subscription you pay for is only to access the online interface.
ChatGPT is different from OpenAI API in terms of subscription.
Further, if you have been temporarily charged $5, which will return to your account in 7 days, it won’t count as subscription yet. You need to purchase atleast $1 to be able to use gpt-4 API.