How to trigger a Gitlab pipeline with Contentful

I have a contentful space and want to trigger a gitlab pipeline. The pipeline should be triggered if something in contentful is edited.

I am using the contentful webhook integration: https://www.contentful.com/marketplace/webhook/gitlab/

But for some reason contentful can’t trigger the gitlab pipeline.
Here is the output

Hi,

when you try to access the URL from the POST request within your browser (or curl with GET request), does that work? The %2F encoded character looks maybe suspicious.

Cheers,
Michael

Hi, changed the url to: https://gitlab.com/newcubator/newcubator-homepage/homepage/pipelines
But now I have HTTP 422.

Hi,

looks as if this method uses the wrong URL endpoint?

https://docs.gitlab.com/ee/ci/triggers/#triggering-a-pipeline
https://docs.gitlab.com/ee/ci/triggers/#triggering-a-pipeline-from-a-webhook

say to the use the REST API endpoints, not the direct project URLs. Unfortunately there seems to be no sourcecode for the contentful product where one could look into and understand its workflow.

Cheers,
Michael