Examine source code of Tab2QR

{
  "author": "James Shih",
  "description": "A minimalist browser extension to send the page you are currently viewing to your mobile device.",
  "name": "Tab2QR",
  "version": "4.0.0",
  "icons": {
    "19": "icons/19.png",
    "38": "icons/38.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "permissions": [
    "activeTab"
  ],
  "optional_permissions": [
    "clipboardWrite",
    "downloads"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{dc3dce74-bf98-4eb4-adc4-75597edb6c5c}",
      "strict_min_version": "109.0"
    }
  },
  "action": {
    "default_title": "Tab2QR",
    "default_icon": {
      "19": "icons/19.png",
      "38": "icons/38.png"
    },
    "default_popup": "src/entries/popup/index.html"
  },
  "manifest_version": 3
}