The gitops repository uses only the single branch "master" to depict the desired state of the deployments.
To stay within the git workflow concepts, changes staged for approval into production are kept in a separate branch "staging-approval" in the same gitops repository. This branch is created and populated automatically as part of the CI/CD pipeline flows.
A pull request between staging-approval and master allows to review the changes which are staged for production. Whoever is responsible for production can review and approve or reject these changes.
If the changes are approved, the branch is merged into master. Optionally, the branch can be deleted.
If the changes are rejected, the pull request is closed and the branch can be deleted (if the branch is not deleted, the changes will reappear in the next pull request).