Examine source code of Web2Kindle

{
  "name": "Web2Kindle",
  "version": "1.0.1",
  "description": "Send web content to your Kindle device",
  "manifest_version": 3,
  "author": "Confidence Okoghenun",
  "homepage_url": "https://web2kindle.megaconfidence.me",
  "action": {
    "default_popup": "extension.html",
    "default_title": "Send Now"
  },
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "host_permissions": [
    "*://*/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d4cc2e4c-29b7-4efc-aaec-a69de72f9c32}"
    }
  }
}