Hello!
I have tried to connect my GitHub account to a plane integration on Plane self-hosted, yet every single time I do, I get redirected from GitHub to plane, I approve the integration on my plane account, and then I get this:
Did you follow this guide to create the GitHub application? The error you are seeing is usually due to incorrect configuration. The troubleshooting section on the same page shows how to fix it. I’d recommend following the guide first depending on whether you are on GitHub Cloud or self-hosted GitHub Enterprise.