docker run -it --rm -p 5901:5901 -v /abc:/root/.config/backintime -e USER=root babim/ubuntubaseinit:backup

attach container and enter vnc password (first run)

Connect to vnc://:5901 via VNC client.

Change password over vncpasswd command in container

VNC to your container. This screen just have terminal
run: backintime-qt4
you can config and run backintime at here