Examine source code of RDU Player

{
  "manifest_version": 3,
  "name": "RDU Player",
  "version": "1.0.4",
  "description": "Audio player Radio Deep Underground",
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "images/icon16.png",
      "48": "images/icon48.png",
      "128": "images/icon128.png"
    }
  },
  "icons": {
    "16": "images/icon16.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "radiodeepunderground@gmail.com",
      "strict_min_version": "102.0"
    }
  },
  "background": {
    "page": "background.html"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage"
  ]
}