$ flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

Note that the directories 

'/var/lib/flatpak/exports/share'
'/home/ben/.local/share/flatpak/exports/share'

are not in the search path set by the XDG_DATA_DIRS environment variable, so
applications installed by Flatpak may not appear on your desktop until the
session is restarted.

Segmentation fault