how to send bytes by http request

### Expected behavior

_No response_

### Actual behavior

_No response_

### Steps to reproduce the problem

Because http body is sensitive, json need to be encrypted byte[]

```
String value="{ \"k1\": 1," \"k2\": 2\"}";
byte[] bytes = value.getBytes();
vars.putObject("body",bytes);
```

JMeter Body Data set ${body}

But what was actually sent out was` [B@39f9e84c`

The actual string received by the server not byte[]

how can i do

### JMeter Version

5.5

### Java Version

1.8

### OS Version

win10