Examine source code of StreamSync

{
  "manifest_version": 3,
  "name": "StreamSync",
  "version": "4.3.0",
  "description": "Resynchronise la musique Spotify sur les rediffusions Twitch",
  "browser_specific_settings": {
    "gecko": {
      "id": "streamsync@streamsync.fr",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "permissions": [
    "storage",
    "identity",
    "tabs",
    "notifications",
    "scripting"
  ],
  "host_permissions": [
    "https://www.twitch.tv/*",
    "https://player.twitch.tv/*",
    "https://api.spotify.com/*",
    "https://accounts.spotify.com/*",
    "https://open.spotify.com/*",
    "https://www.youtube.com/*",
    "https://streamsync.fr/*",
    "http://localhost:3000/*",
    "http://127.0.0.1:3000/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.twitch.tv/*",
        "https://player.twitch.tv/*"
      ],
      "js": [
        "i18n/locales.js",
        "i18n/i18n.js",
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "background": {
    "scripts": [
      "i18n/locales.js",
      "i18n/i18n.js",
      "service-worker.js"
    ]
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "StreamSync",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  }
}