curl --request POST \
  --url https://api2.rhombussystems.com/api/user/metadata/saveUserMetadataFields \
  --header 'Content-Type: application/json' \
  --header 'x-auth-apikey: <api-key>' \
  --header 'x-auth-scheme: <x-auth-scheme>' \
  --data '
{
  "fieldValueMap": {},
  "userUuid": "AAAAAAAAAAAAAAAAAAAAAA"
}
'

{
  "templateMap": {},
  "userFieldValueMap": {}
}