chromium/chrome/test/data/extensions/api_test/incognito/popup/manifest.json

{
  "name": "Incognito popup tester",
  "version": "0.1",
  "manifest_version": 3,
  "description": "apitest for popups in incognito mode",
  "permissions": [
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html"
  }
}