curl --request POST \
  --url https://api.shoppex.io/dev/v1/customers/{id}/wallet/credit \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "amount": "10.00",
  "type": "PROMO",
  "description": "Goodwill credit"
}
'

{
  "data": {
    "transaction_id": "txn_credit_1",
    "amount": 10,
    "currency": "EUR",
    "new_balance": 25,
    "available_balance": 22.5,
    "wallet_id": "wallet_1"
  }
}