I wanted to install Systemback on my ubuntu 20.04 and found this page.
When I ran systemback, I get this error message.

ckim@ckim-ubuntu:~$ sudo systemback&

[1] 220231

ckim@ckim-ubuntu:~$ No protocol specified

No protocol specified

qt.qpa.xcb: could not connect to display :2

qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.

This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.



Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.

What should I install and how? (fwiw, I'm doing it on a vnc client on a windows 10 machine at work, and connecting to the windows 10 machine from home) Thanks in advance!

ADD : I did sudo apt install qt5dxcb-plugin and tried again, it didn't work. (said plugin "xcb"couldn't beload even though it was found) But when I ran it on console window, systemback worked. I used to run systemback on vnc window too on 16.04 I think.