Examine source code of listening to

{
  "manifest_version": 3,
  "name": "listening to",
  "version": "1.0.1",
  "description": "youtube music discord rich presence bridge",
  "host_permissions": [
    "http://localhost:2945/*",
    "http://127.0.0.1:2945/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://music.youtube.com/*"
      ],
      "js": [
        "watcher.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "@listening-to",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}