# Defend

## Overview

The `defend` method submits formal defense against a chargeback.

## Request Fields

| Field         | Type   | Required | Description         |
| ------------- | ------ | -------- | ------------------- |
| `disputeId`   | String | Yes      | Dispute ID          |
| `reasonCode`  | String | Yes      | Defense reason code |
| `explanation` | String | Yes      | Explanation         |

## Example

```java
Map<String, Object> request = new HashMap<>();
request.put("disputeId", "dp_xxx");
request.put("reasonCode", "product_or_service_provided");
request.put("explanation", "Product delivered successfully");

Map<String, Object> response = disputeClient.defend(request);
```