Minimize/Hide any window to tray icon to be restored later.
Some processes might not be compliant. Therefore their windows cannot be hidden, nor removed from the taskbar.
https://www.softpedia.com/get/PORTABLE-SOFTWARE/System/System-Enhancements/Minimize-ToTray.shtml
Download: https://github.com/sandwichdoge/MinimizeToTray/releases/