curl --request GET \
  --url http://localhost:3001/api/v1/business/customers/email/{email} \
  --header 'x-api-key: <x-api-key>'

{
  "success": true,
  "data": {
    "customerId": "<string>",
    "email": "<string>",
    "totalPayments": 123,
    "totalSpent": 123,
    "userId": "<string>",
    "firstName": {},
    "lastName": {},
    "defaultPaymentMethod": {}
  }
}