Examine source code of MP3 Cut - Audio Trimmer

{
  "manifest_version": 3,
  "name": "MP3 Cut - Audio Trimmer",
  "version": "1.0",
  "description": "Audio Cutter - Trim or cut any audio file online.",
  "permissions": [
    "storage",
    "unlimitedStorage"
  ],
  "host_permissions": [
    "https://mp3cut.org/*"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "Audio Studio",
    "default_icon": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://mp3cut.org/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "audiostudiopro@yourdomain.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "128": "icon.png"
  }
}