Newbie qustions

Hi there.
I have a couple of questions, could you please help me?

  1. How can I minimize application to tray? In my case I need to minimize Thunderbird.
  2. I tried to configure KDE Connect application, but PC and my Phone don’t see each other. ping goes from one device to another, but KDEConnect shows nothing. How can I fix that issue? Any advices?
  3. How can I backup KDE configuration? For example when I need to move my configuration from one OS to another. From Debian to Ubuntu.

Debian 12
KDE 5.27.5

Thanks in advance.