I have installed GitLab plugin but I am not able to use it because configuration in Jenkins management settings fails on authentication.

I am not able to get GitLab plugin in Job configuration in SCM section. I guess it is because of this error.

First I generated API Key, created authentication for GitLab plugin according to tutorial.

It appeared in the Combo Box. Selected it, set URL http://git.ads.local same in both text fields and pressed test button. It failed on authentication. No stack trace was displayed.

So I tried to use Username/Password but the authentication did not appear in the Combo Box at all.

I am using Http Proxy configured in Jenkins because the GitLab is in company network and no-proxy-host is also *.ads.local. My Maven builds connects to Nexus in the same network domain and this works.

Where can I find logs of GitLab plugin? I would attach it in Jira.