ESP 32 Unable to expose string variable

Using the following configuration on ESP 32 I see an empty string:
```
// Config
char nowstring[4] = "Test";
rest.variable("test", &nowstring, true);
```
```
//Output
{"variables": {"test": ""}, "id": "1", "name": "esp32", "hardware": "esp32", "connected": true}
```
Am I missing something?