Examine source code of Amazon Book Research Helper

{
  "manifest_version": 3,
  "name": "Amazon Book Research Helper",
  "description": "Writing to market? This extension shows the most important information about a book right at the top of the page.",
  "version": "1.3.3",
  "author": "Ian L.",
  "browser_specific_settings": {
    "gecko": {
      "id": "{a0366882-fa8c-49a2-918f-5488b4efe5a0}",
      "strict_min_version": "109.0"
    }
  },
  "icons": {
    "48": "assets/icon48.png",
    "96": "assets/icon96.png",
    "128": "assets/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.amazon.com/*",
        "*://*.amazon.ca/*",
        "*://*.amazon.com.au/*",
        "*://*.amazon.co.uk/*"
      ],
      "run_at": "document_end",
      "css": [
        "amazon.css"
      ],
      "js": [
        "amazon.js"
      ]
    },
    {
      "matches": [
        "https://kindlepreneur.com/amazon-kdp-sales-rank-calculator/*"
      ],
      "js": [
        "kp.js"
      ]
    },
    {
      "matches": [
        "https://www.tckpublishing.com/amazon-book-sales-calculator/*"
      ],
      "js": [
        "tck.js"
      ]
    },
    {
      "matches": [
        "https://www.bklnk.com/*"
      ],
      "js": [
        "bklnk.js"
      ]
    }
  ],
  "host_permissions": [
    "*://*.amazon.com/*",
    "*://*.amazon.ca/*",
    "*://*.amazon.com.au/*",
    "*://*.amazon.co.uk/*",
    "https://www.tckpublishing.com/amazon-book-sales-calculator/*",
    "https://kindlepreneur.com/amazon-kdp-sales-rank-calculator/*",
    "https://www.bklnk.com/*"
  ]
}