Web API Add Custom Playlist Cover Image

[Opticz0005]

EDIT: I got it working. Used some work arounds and fought the APItooth and nail but finally got it. Reply if you need help!

Making a Playlist manager with the Spotipy API and no matter what I do I cannot get the endpoint to accept what I give it.

What am I doing so wrong?

Can provide any code snippets you request.

I understand the image needs to be b64 encoded, less than 256kb and a jpeg.