Examine source code of NFC Reader

{
  "manifest_version": 3,
  "name": "NFC Reader",
  "version": "0.0.26",
  "description": "Read NFC-A cards from USB reader and auto-fill input fields",
  "browser_specific_settings": {
    "gecko": {
      "id": "nfc@nfcreader.info",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "nativeMessaging",
    "activeTab",
    "storage"
  ],
  "background": {
    "service_worker": "background/background.js",
    "type": "module",
    "scripts": [
      "background/background.js"
    ]
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "content/content.js"
      ],
      "run_at": "document_idle"
    }
  ]
}