Custom gitlab project service for Azure DevOps

Hi! I do need to integrate GitLab Merge requests with Azure DevOps. GitLab has to trigger Azure Pipeline and get information regarding build result (success or fail) and allow Merge if the pipeline was succeeded.
For this purpose in Jenkins we have GitLab plugin but I didn’t get any information how to proceed it with Azure. I think that I need to create project service but didn’t find any useful documentation for that. Does anyone have idea how to create custom service for GitLab?