Examine source code of Net Radio

{
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "net-radio@igor.jerosimic",
      "strict_min_version": "60.0"
    }
  },
  "name": "Net Radio",
  "short_name": "Net Radio",
  "version": "3.4.1",
  "description": "Slušajte radio stanice preko internet streama direktno u browseru.",
  "homepage_url": "https://www.igorware.com/extensions/net-radio?referrer-ver=firefox-ext-manager",
  "developer": {
    "name": "Igor Jerosimić",
    "url": "https://www.igorware.com/extensions/net-radio"
  },
  "background": {
    "scripts": [
      "logger.js",
      "cross.js",
      "storage.js",
      "plugin.js",
      "background.js"
    ],
    "persistent": true
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "icons": {
    "16": "images/icon_016.png",
    "19": "images/icon_019.png",
    "32": "images/icon_032.png",
    "38": "images/icon_038.png",
    "48": "images/icon_048.png",
    "64": "images/icon_064.png",
    "128": "images/icon_128.png"
  },
  "browser_action": {
    "default_title": "Net Radio se učitava...",
    "default_icon": {
      "16": "images/icon_loading_016.png",
      "32": "images/icon_loading_032.png",
      "64": "images/icon_loading_064.png"
    }
  },
  "commands": {
    "player-play": {
      "description": "Pusti radio stanicu"
    },
    "player-stop": {
      "description": "Zaustavi radio stanicu"
    },
    "player-prev": {
      "description": "Prethodna radio stanica"
    },
    "player-next": {
      "description": "Sledeća radio stanica"
    },
    "volume-up": {
      "description": "Pojačaj zvuk"
    },
    "volume-down": {
      "description": "Smanji zvuk"
    },
    "volume-mute": {
      "description": "Isključi zvuk (mute)"
    }
  },
  "content_security_policy": "default-src 'self'; connect-src https://api.igorware.com; font-src 'none'; img-src 'self' https://download.igorware.com; media-src http:; object-src 'none'; style-src 'unsafe-inline'",
  "permissions": [
    "storage",
    "https://api.igorware.com/*"
  ]
}