curl --request GET \
  --url https://api.zupy.com/api/v2/customers/{id}/z-balance/ \
  --header 'X-API-Key: <api-key>'

{
  "data": {
    "z_balance": "<string>",
    "wallet_address": "<string>",
    "has_wallet": true,
    "error": "<string>"
  },
  "meta": {
    "cursor": "<string>",
    "has_next": true,
    "count": 123
  }
}