Examine source code of Polyreader

{
  "manifest_version": 3,
  "description": "The official Firefox extension for Polyreader, the send-to-Kindle service.",
  "action": {
    "default_title": "Polyreader",
    "default_icon": {
      "16": "static/icon.16.png",
      "32": "static/icon.32.png"
    }
  },
  "permissions": [
    "scripting",
    "storage",
    "activeTab"
  ],
  "name": "Polyreader",
  "version": "0.0.44",
  "icons": {
    "16": "static/icon.16.png",
    "32": "static/icon.32.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "firefox@polyreader.app",
      "strict_min_version": "109.0"
    }
  }
}