How to pass variables to trigger project correctly?

Hello, can i use variables in trigger downstream pipelines?

I need trigger the pipeline in downstream project only if i pass variables from upstream project:

debug-triggers:
  stage: pre_verify_external_stage
  rules:
    - if: $GITLAB_GROUP
    - if: $GITLAB_PROJECT
  trigger:
    project: $GITLAB_GROUP/$GITLAB_PROJECT
    strategy: depend

But rigth now if i pass this variables the trigger starts on pause and freeze in this condition.
Current using instance is 14.1.2-ee.