How make to minimize app to tray on close

Question

I use this page to create a WhatsApp application, but I want when I close or minimize app it's going to tray and not close complete.

And how to add startup to minimize.

I test alltray, but not work in 19.04

Answer 1

Using WhatsDesk downloadable from the Ubuntu Software Centre select Show/Hide WhatsDesk and then go to Tools and select Close Window and Exit and/or Skip Taskbar as required.