Examine source code of Domain Password Hasher

{
  "manifest_version": 3,
  "name": "Domain Password Hasher",
  "version": "1.0",
  "description": "Generate Base64(SHA-256(password_domain))",
  "permissions": [
    "activeTab"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "dustheap@gmail.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}