Managing GitLab Protected Branches by CLI?

I am trying to deprotecting branches in my GitLab Group.

Till now, I enter in to the certain project > Settings > Repository > Protected Brancheds(Expand) > Unprotect Branch

It’s OK when the number of projects are small.

But there are several projects(50+) in my group.

So when I try to handle permission that protects branches, I have to enter in every GitLab projects… like above…

I want to managing branch protect policy by command-line-tool. Is there any good solution?

I installed GitLab using docker-compose and it runs on the docker.

The GitLab container uses host mounted volumes to store persistent data: /srv/gitlab/data /srv/gitlab/logs /srv/gitlab/config

I’ve look around these directories but nothing found…

Again, How can I handle branch protection by command-line-tool? Many Thanks!

I think I have to use REST API.