Examine source code of Nam Radio

{
  "manifest_version": 2,
  "name": "Nam Radio",
  "short_name": "Nam Radio",
  "description": "Listen Nam Radio with Firefox Browser.",
  "version": "1.0.1",
  "applications": {
    "gecko": {
      "id": "namradio@greenitsolution.net",
      "strict_min_version": "57.0a1"
    }
  },
  "permissions": [
    "*://music-station.live/*",
    "storage",
    "notifications"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "background": {
    "page": "background.html"
  },
  "options_ui": {
    "page": "options.html",
    "chrome_style": true,
    "open_in_tab": false
  },
  "browser_action": {
    "default_icon": {
      "16": "assets/images/icon16.png",
      "24": "assets/images/icon24.png",
      "32": "assets/images/icon32.png",
      "48": "assets/images/icon48.png"
    },
    "default_popup": "popup.html",
    "default_title": "Nam Radio"
  },
  "icons": {
    "16": "assets/images/icon16.png",
    "48": "assets/images/icon48.png",
    "128": "assets/images/icon128.png"
  },
  "commands": {
    "play-pause-station": {
      "suggested_key": {
        "default": "MediaPlayPause",
        "mac": "MediaPlayPause"
      },
      "description": "Toggle playing the selected station"
    },
    "pause-station": {
      "suggested_key": {
        "default": "MediaStop"
      },
      "description": "Pause the selected station"
    },
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+N"
      }
    }
  },
  "web_accessible_resources": [
    "defaultStation.json",
    "icon48.png",
    "icon48-dark.png",
    "options.html"
  ]
}