request to /auth/token returns a blank reply, is this by design?

```
curl -X POST -u "sms:MYPASS" -H "Content-Type: application/json" -d '{"ttl": 3600,"scopes": ["messages:send","messages:read","devices:list"]}' \
    http://LOCALIP:8080/auth/token
```

swagger says request is supported, latest code from **master** .. https://capcom6.github.io/android-sms-gateway/#/
maybe iam missing something?