github action, trigger filter does not works as doc described

Question

I have a github action workflow yml file to tets the trigger filter

name: test

on:
  pull_request:
    branches-ignore:
      - 'rel_test'

jobs:
  test_job:
    runs-on: ubuntu-latest

    steps:
      - name: print_pr_context
        env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
        run: echo "$GITHUB_CONTEXT"

according to the doc, when the branch name is rel_test, workflow run should be skipped. But when I have a branch named rel_test, and when open a PR using this branch, the github workflow runs automatically.

Not sure where it goes wrong or how can I see the logic logs of why this workflows runs in github.

Thank you

try running on GH, expected behaviour likes doc suggest but not.