curl --request POST \
  --url https://{yourDomain}/api/service/webhook-event/mandate-setup-failed \
  --header 'Content-Type: application/json' \
  --data '{
  "id": "<string>",
  "type": "mandate_setup_failed",
  "date": "<string>",
  "payload": {
    "referenceId": "<string>",
    "existingMandateId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "error": {
      "code": "<string>",
      "message": "<string>"
    }
  }
}'