How to add a Java project to GitLab from IntelliJ IDEA

Create a project or choose any existing project.

Go to GitLab and create a new space for the project.

Copy the URL of the repository.

Go back to IntelliJ IDEA.

Right-click over the project and choose Git | Manage Remotes...

Click "+" (add symbol) and paste the repository URL in there.

Click Ok on both dialog windows. The repository will be added.

Go to the Git tool and select all the Changes.

Specify a commit message and click Commit and push.

A push commit dialog will be opened, click the "Push" button.

Now the project files will be in GitLab's project list.