Examine source code of GeoGuessr Notes

{
  "manifest_version": 2,
  "name": "geoguessr-notes",
  "version": "1.3",
  "content_scripts": [
    {
      "matches": [
        "https://www.geoguessr.com/game/*",
        "https://www.geoguessr.com/challenge/*"
      ],
      "js": [
        "geoguessr-notes.js"
      ],
      "run_at": "document_idle"
    }
  ]
}