name: 'Issue/PR Milestones'

on:
  pull_request:
    types: [opened, reopened]
  issues:
    types: [opened, reopened]

jobs:
  set:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: actions/github-script@v3
        with:
          github-token: ${{secrets.GITHUB_TOKEN}}
          script: |
            const milestone = 3
            github.issues.update({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              milestone
            })