How to Fix Node.js "Application Error" on Azure when using GitHub Actions

name: Build and Deploy Node.js App

on:
  push:
    branches: [main]

jobs:
  deploy:
    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v5

    - name: Setup Node.js
      uses: actions/setup-node@v4
      with:
        node-version: '20.x'

    - name: Install dependencies
      run: npm install

    - name: Build (if any)
      run: npm run build --if-present

    - name: Set Azure startup command
      uses: azure/cli@v2
      with:
        inlineScript: |
          az webapp config set \
            --name <YOUR_APP_NAME> \
            --resource-group <YOUR_RESOURCE_GROUP> \
            --startup-file "node index.js"

    - name: Deploy to Azure
      uses: azure/webapps-deploy@v3
      with:
        app-name: "<YOUR_APP_NAME>"
        publish-profile: ${{ secrets.AZURE_WEBAPP_PUBLISH_PROFILE }}
        package: .