Can't load testing

Hi,

I’m new with Vaadin and I am developping an application server-client with Vaadin. I have a Java Project which launch a Vaadin website with Jetty Runner from a Vaadin Project and a Swing Project for the server application. I have a JavaFX Project to show the website with a webviewer. The Vaadin Project and the Swing Project shared a required Common Java Project to communicate data.
![Structure of the project]
(https://i.imgur.com/w028AWZ.png)

I have a button on the website and when I click the event notify a listener in the Common Project.

I tried to load test the jetty server with The Grinder, Gatling and JMeter. I tried to use Record Controller but it can’t detect any request. I searched the request emit with the button, but I couldn’t find it.

Is it impossible I load test this or I make something wrong ? I use Vaadin 14.

Thanks in advance for any-and-all help!