Create referral user

curl --request POST \
  --url https://admin.snagsolutions.io/api/referral/users \
  --header 'Content-Type: application/json' \
  --header 'X-API-KEY: <api-key>' \
  --data '{
  "referralCode": "<string>",
  "referralCodeId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "userIds": [
    "3c90c3cc-0d44-4b50-8888-8dd25736052a"
  ]
}'

{
  "message": "<string>"
}