
In case you may be familiar with the stack: this is setup in django's rest oauth toolkit. If not, that's ok too, just dropping that bit in case it's useful to anyone else.
This leads to the issue I'm having. After the authorize screen (our own):

I get the following error from https://zis.zendesk.com/api/

This is where I'm quite stuck. I had thought that with it returning the code, aka the auth token, that I'd be in the green. Perhaps I'm missing something obvious. Please let me know.
Would you be able to provide the relevant code snippets (omitting any identifying info)? This will help us to be able to debug the issue much more effectively.
Thanks!