The say they have a REST API. Could you use that directly from Python instead of using an SDK?
I've seen a similar situation with payment processors, where they have SDKs in a variety of languages, but not the one I'm using (our back end is in Perl), so I use the underlying low level API.
Amusingly, it often happens that I look at their Java or PHP SDKs, which involve seemingly a bewildering number of classes and methods, and find that just using their underlying REST API directly is massively simpler, clearer, and takes less code, to the point I don't use their SDKs even if I am working in a language they have an SDK for.
But payment processing is pretty simple. Third party authentication is probably more complicated, and so it could be that the SDKs are doing a lot more than just providing a fairly straightforward wrapper for the underlying low level API.