{
    "appId": "testApp.com",
    "type": "u2f_register_request",
    "registerRequests": [
        {
            "version": "U2F_V2",
            "appId": "testApp.com",
            "challenge": "9tLLsBwS_ovqZaOqbxAPV6V6xzgwIcFdAcqhCoM605A"
        }
    ],
    "registeredKeys": []
}