The REST request for a clone-ticket from the vsphere-ui service can produce the following response codes.

Table 1. Response Codes to clone-ticket Request
Response Code Description
201 Session clone ticket was successfully created and returned.
The body type is application/json, and the response body has this format: 
{
"session_clone_ticket": "string"
}
401 The request is not properly authenticated.
403 The remote plug-in is not registered with the vCenter Server instance identified by the specified UUID.
404 There is no vCenter Server instance identified by the specified UUID.