Auto merge PR on adding label and trigger deployment if the branch supports it. Must have PAT(Personal access token) added to GH action.

auto-merge.yml

name: Auto Merge and Push on Label

on:
  pull_request_target:
    types: [labeled]

jobs:
  auto-merge-and-push:
    runs-on: ubuntu-latest
    if: github.event.label.name == 'In dev'
    steps:
    - name: Checkout repository
      uses: actions/checkout@v2
      with:
        ref: ${{ github.head_ref }}
        fetch-depth: 0
        token: ${{ secrets.PERSONAL_ACCESS_TOKEN }}

    - name: Merge PR
      run: |
        git config --global user.name 'CI'
        git config --global user.email 'change-this-email@users.noreply.github.com'
        git fetch origin
        git checkout develop
        git merge --no-ff ${{ github.head_ref }} -m "Merging PR #${{ github.event.pull_request.number }}"
        git push origin develop