Jira GitLab DVCS integration fails

I have fallowed these resources:


The integration from gitlab TO jira works but the one from Jira to gitlab fails with

I have made many attempts to create the integration .
I want answers to these questions:

  1. Does the GitLab instance have to be HTTPS or can it HTTP to create the Oauth authentication?
  2. Is a higher level of support of GitLab required for this integration like a gold edition?
    I am using version 12.8.5 community edition self-hosted

I am passing a top level group

Are there tests with URLs that can mimic the process and give the root cause of the issue