curl --request POST \
  --url https://api2.rhombussystems.com/api/accesscontrol/assignAccessControlCredential \
  --header 'Content-Type: application/json' \
  --header 'x-auth-apikey: <api-key>' \
  --header 'x-auth-scheme: <x-auth-scheme>' \
  --data '
{
  "credentialHexValue": "1234567890ABCDEF",
  "userUuid": "AAAAAAAAAAAAAAAAAAAAAA"
}
'

{
  "credential": {
    "createdAtMillis": 123,
    "endDateEpochSecExclusive": 123,
    "lastUsedAccessControlledDoorUuid": "AAAAAAAAAAAAAAAAAAAAAA",
    "lastUsedAtMillis": 123,
    "lastUsedLocationUuid": "AAAAAAAAAAAAAAAAAAAAAA",
    "lowercaseHexValue": "<string>",
    "managedCredUuid": "AAAAAAAAAAAAAAAAAAAAAA",
    "note": "<string>",
    "orgUuid": "AAAAAAAAAAAAAAAAAAAAAA",
    "startDateEpochSecInclusive": 123,
    "type": "STANDARD_CSN",
    "updatedAtMillis": 123,
    "userUuid": "AAAAAAAAAAAAAAAAAAAAAA",
    "uuid": "AAAAAAAAAAAAAAAAAAAAAA",
    "value": "<string>",
    "workflowStatus": "ACTIVE"
  }
}