Open Gitlab and go to the "Admin Area".
Click on the "System Hooks" menu item.
Fill the "URL" field and select the checkboxes like the screenshot down below.
Your have to replace <GRAVITY_URL> in the "URL" field by the url of your Gravity instance.
The SSL verification option is optional and depends on your Gitlab setup.
Click on "Add system hook".
Your Gitlab is connected to your Gravity. 🎉