How to version or tag incrementally in Gitlab CI/CD when merging from Production to Release branch

I’m working on a project with different micro-services (each service build using different language such as nodejs, java and C#). I’m using Gitlab CICD pipeline and I wanted to tag or give a version number when merging from my production branch to release branch. I tried looking at git tags but that seems something that is done manually. I wanted gitlab to tag V 1.0 , 1.1 …etc when the merging happens and my CICD runs successfully .

Looking for help/ answers ASAP