Examine source code of Manga Tracker Sync

{
  "manifest_version": 3,
  "name": "__MSG_extName__",
  "version": "1.1.1",
  "description": "__MSG_extDescription__",
  "default_locale": "pt_BR",
  "permissions": [
    "storage",
    "alarms",
    "permissions",
    "scripting"
  ],
  "optional_host_permissions": [
    "<all_urls>"
  ],
  "externally_connectable": {
    "matches": [
      "https://mangastracker.vercel.app/*",
      "http://localhost:3000/*",
      "http://127.0.0.1:3000/*"
    ]
  },
  "icons": {
    "16": "assets/icons/icon-16.png",
    "48": "assets/icons/icon-48.png",
    "128": "assets/icons/icon-128.png"
  },
  "background": {
    "scripts": [
      "src/background.js"
    ],
    "service_worker": "src/background.js",
    "type": "module"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "manga-tracker-sync@mangalist.app",
      "data_collection_permissions": {
        "required": [
          "authenticationInfo",
          "websiteActivity"
        ]
      }
    }
  },
  "action": {
    "default_title": "__MSG_extActionTitle__",
    "default_popup": "src/popup.html",
    "default_icon": {
      "16": "assets/icons/icon-16.png",
      "48": "assets/icons/icon-48.png",
      "128": "assets/icons/icon-128.png"
    }
  }
}