I have installed snapd according to official how-to.
Then installed two snaps: telegram-desktop and notepadqq.
Neither can really run.
For example, telegram-desktop output (start):
No protocol specified
QXcbConnection: Could not connect to display :0.0
I am sure I am doing something wrong, because cannot be that everybody using it and on opensuse Tumbleweed 20190904 it is not working at all.
Can you please help me to check together some obvious staff, from simple to complex together?