curl --request GET \
  --url https://api.useduro.com/v1/customers/ref/{ref} \
  --header 'Authorization: Bearer <token>'

{
  "id": "<string>",
  "email": "<string>",
  "phone": "<string>",
  "name": "<string>",
  "merchantRef": "<string>",
  "blacklisted": true,
  "blacklistReason": "<string>",
  "createdAt": "<string>"
}