This action will help you to run phpcs (PHP_CodeSniffer) with GitHub Actions platform. It also supports annotations out of the box — you don't need to use any tokens to make it work.
Add the following code to .github/workflows/phpcs.yml file.
name: PHPCS check
on: pull_request
jobs:
phpcs:
name: PHPCS
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: PHPCS check
uses: agoja/drupal-phpcs-action@v0.1