Hello @keithbenjamimicronco
My best guess is that your Python code is incorrect and you’re not constructing and sending the Basic Auth credentials properly.
If you look more closely at the documentation for the Get fields endpoint, you will see that it requires no authentication by default and can be accessed anonymously, so your request with faulty credentials is just being processed as unauthenticated (anonymous), which is leading you to think you have authenticated properly, when in fact you never did.
You’ve not said if the Get create metadata issuetypes endpoint is the only other one you’ve tried that is giving you an error about authentication. The fail-safe way to test whether your Python based requests are sending authentication properly is to start with a request to the Get Current User endpoint.