Examine source code of In-page QR Code Scanner

{
  "manifest_version": 3,
  "name": "QR Code Scanner",
  "version": "1.1",
  "description": "Scan QR codes on pages, upload or paste images, or open camera to scan QR codes",
  "permissions": [
    "activeTab",
    "scripting",
    "storage",
    "clipboardRead",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "qrcode-scanner@kycis.com",
      "strict_min_version": "109.0"
    }
  },
  "host_permissions": [
    "<all_urls>"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "lib/jsQR.js",
        "qrScanner.js",
        "content.js"
      ]
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  }
}