status: 200

{
"UserConfirmed": false,
"CodeDeliveryDetails": {
"Destination": "t***@t***.by",
"DeliveryMedium": "EMAIL",
"AttributeName": "email"
},
"UserSub": "4700c679-a60e-41fc-9c0d-12c0aa8a546c"
}

status 500
{
"Error": "User already exists",
"Reference": "f4dc4553-a211-11e8-90ee-65ae0f6210b5"
}