Examine source code of DomainToolBox

{
  "manifest_version": 3,
  "name": "DomainToolBox",
  "description": "A simple DNS lookup tool inspired by MXToolbox. It can retrieve the following records: A, AAAA, MX, TXT, CNAME, SOA, NS, and CERT.",
  "version": "1.2.0",
  "icons": {
    "128": "icons128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "csuszy@bencedev.hu"
    }
  },
  "permissions": [],
  "action": {
    "default_popup": "popup.html"
  },
  "host_permissions": [
    "http://*/*",
    "https://*/*"
  ]
}