Self-hosted GitLab: Cannot connect to public application

Problem to solve

I have a user trying to connect to our publicly-facing application, Pipedream, from their self-hosted instance of GitLab.

Instead of going through the typical authorization flow, they consistently hit the following error:

“Client authentication failed due to unknown client, no client authentication included, or unsupported authentication method”

This works without issue for GitLab-hosted accounts. Can someone confirm if self-hosted GitLab requires customers to configure their own OAuth clients, or if there’s a way to set this up so that it works with publicly-facing clients?

Steps to reproduce

Try to connect hosted account on Pipedream (GitLab API Integrations - Pipedream), and self-hosted GitLab.


Provide screenshots from the GitLab UI showing relevant configuration, if applicable.
On self-managed instances, add the relevant configuration settings or changes.


Please select whether options apply, and add the version information.