Explanation of where GitHub Org Check flow should go?

**Describe your question/**
I'm trying to follow https://goauthentik.io/integrations/sources/github/#checking-for-membership-of-a-github-organisation but I cannot determine where exactly this is supposed to go within the flows.

I've tried placing it in numerous places, including various flow stages, in the Oauth social provider, in the application, and all of them fail. Some simply do nothing (i.e. allow a non-org user to log in), but most throw exceptions due to the first conditional not being valid (a KeyError on `context["source"]`).

**Relevant infos**
On version 2023.10.

**Screenshots**
N/A

**Logs**
N/A

**Additional context**
This documentation should be much more explicit about where this should be put for it to work.