Using Spring Boot 3.1.3

My Application class:

@SpringBootApplication
@EnableAsync
public class Application {

  public static void main(final String[] args) {
    SpringApplication.run(Application.class, args);
  }
}

My rest controller:

@RestController
public class MainController {

  @GetMapping
  @Async
  public Future<String> show() {
    return CompletableFuture.completedFuture("Jordi");
  }
}

The response of the operation is:

{
  "cancelled": false,
  "done": true
}

When it should be “Jordi”.

However if I remove the @Async annotation it works as expected.

Am I doing something wrong?