Authenticate to GCLOUD using ID_TOKEN (Gitlab OIDC)

I followed the steps from all thee documentations
( Google Cloud workload identity federation and IAM policies | GitLab

( and Google Cloud integration | GitLab

( to cloud services | GitLab

( OpenID Connect with GCP Workload Identity Federation | GitLab

( Connect (OIDC) Authentication Using ID Tokens | GitLab

( YAML syntax reference | GitLab
to simplify authentication of GitLab CI/CD pipelines with Google Cloud but the first issue I have is that after creating the workload Identity pool and OIDC provider and set some attribrutes and assertions, my IAM principal is not passing the SUBJET_ATTRIBUTE_VALUE. here is how it looks: principal://
Also not sure why I have principal instead of pricipalSet.
Regardless of this not sure how to get the credentials and actually use them for the service account impersonation.
I added this to my job in gitlab-ci.yaml file:


    - apt-get update -y
    - apt-get install -y curl
    - apt-get install -y jq
    - chmod +x ./
    - ./

Please any help?