Sonarcloud migration

Currently I’m using GitHub and we are migrating to Gitlab. I’m already aware that there is no migration mechanism, however I didn’t see a way to add a Gitlab repository on my account. Do I need to setup a new organization from scratch for that?

Yes!

If you are migrating projects to another organization (either on the same repository platform), you will need to create a new SonarCloud organization to bind to the new platform organization and re-import the projects you want to analyze.