The following solution triggers a GET request and converts the returned JSON response into User:
Jsonb jsonb = JsonbBuilder.create();
HttpClient client = HttpClient.newHttpClient();
HttpRequest requestGet = HttpRequest.newBuilder()
.uri(URI.create("https://reqres.in/api/users/2"))
.build();
HttpResponse<User> responseGet = client.send(
requestGet, JsonBodyHandler.jsonBodyHandler(jsonb, User.class));
User user = responseGet.body();