Examine source code of KDP Uploader

{
  "name": "KDP Uploader",
  "version": "1.1.4",
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "kdpuploader@gmail.com",
      "strict_min_version": "55.0"
    }
  },
  "description": "Upload Paperbacks and Kindle eBooks to KDP platform has never been so Easy",
  "homepage_url": "http://kdpuploader.com",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "default_locale": "en",
  "browser_action": {
    "default_icon": "icons/icon19.png",
    "default_title": "KDP Uploader v1.1.4"
  },
  "background": {
    "scripts": [
      "src/bg/background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "storage",
    "https://*.amazon.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://kdp.amazon.com/*",
        "*://account.kdp.amazon.com/*"
      ],
      "all_frames": true,
      "js": [
        "src/inject/inject.js"
      ],
      "run_at": "document_idle"
    }
  ]
}