electron/spec/fixtures/extensions/mv3-service-worker/manifest.json

{
  "name": "MV3 Service Worker",
  "description": "Test for extension service worker support.",
  "version": "1.0",
  "manifest_version": 3,
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "main.js"
      ],
      "run_at": "document_start"
    }
  ],
  "background": {
    "service_worker": "background.js"
  }
}