When 429 Occurs Despite Sufficient Credits with OpenAI API

Despite having credits in the OpenAI API, during an API request, I encountered the following response:

HTTP 429

{
    "error": {
        "message": "You exceeded your current quota, please check your plan and billing details. For more information on this error, read the docs: https://platform.openai.com/docs/guides/error-codes/api-errors.",
        "type": "insufficient_quota",
        "param": null,
        "code": "insufficient_quota"
    }
}

Even after recreating the API key and project, the situation did not change.

As a test, adding an additional $5 charge resolved the issue.

It seems likely that this occurs when using the free tier immediately after creating an account and then adding credits.