Cant access elements from java swing application in appium desktop

I would like to test our java swing application with Appium, but I am having troubles with accessing its elements trough Appium Desktop (even XML doesn’t show anything more). All I can see is maximize, minimize and close buttons in inspector. This is probably a problem of application itself - what attributes have to be set for example for a Jbutton in application so Appium is able to see this element?

Appium-windows 1.21.0

Thank you.