curl --request POST \
  --url https://api-dev.withflock.com/referrals/validate-code \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '{
  "referralCode": "<string>"
}'

{
  "isValid": true,
  "referredBy": {
    "id": "<string>",
    "externalUserId": "<string>",
    "email": "<string>",
    "name": "<string>"
  }
}