Two ways to contribute to a GitLab repository, depending on whether you are already known to and trusted by the repository owner
In my experience, a contribution to a repository doesn’t come out of nowhere. Often you will have been having a bit of a chat in someone’s repository issues (more on that later), and they will say, “Hey, that’s a great idea! Do you want to submit a merge request?!”. This is your invitation to contribute!
By “stranger” I mean that you are not one of the people who have access to make changes to the repository without going through a gate keeper. Your gate keeper is the process of the pull request which is review by the repository owner.
You can also submit changes in a more straight forward way if you have ben added as a collaborator to a repository. This requires the repository owner to have agreed this with you in advance, which we’re not going to assume has happened here. You can follow a detailed presentation on how to add collaborators to your repository here
This documentation needs to be updated for GitLab