Gitlab IPs whitelisting at Jenkins Server

We use Gitlab.com for our repos and we use Jenkins for CICD. We want to close the 80,443 ports for out Jenkins server and whitelist IPs or Gitlab.com so that our repos can be triggered to the Jenkins.

Is there any workaround about this?

The IP ranges for GitLab.com can be found here: GitLab.com settings | GitLab