Klass, I am interested in your custom component, in whatever way it’s convenient to share.
Stanislaw, Klass is correct, I’m suggesting something simpler/quicker than setting up ‘print’.
The ‘Show Alert message’ component is pretty close, just would be nice to eliminate the ‘OK’ click. Besides the timed display, I’d suggest considering a show-only-in-development feature: a ‘show in publication’ checkbox (that defaults to unchecked) or logic input (that defaults to false), allowing turn on/off from an App Data property. This is useful in apps that ‘bounce’ back and forth between development and production.
FWIW, Hanna Syniavska’s (HowTo/Cookbook) post (How to create a dropdown in UI Builder) shows a neat dropdown that uses Theme > Extension > CSS code. Not convenient for the quick message I’m suggesting, but very elegant and effective in a production app.