i3wm is by far my most used Window Manager (WM), who cares about Desktop Environments (DEs) :). On DEs such as XFCE, KDE, GNOME, LXDE, etc it is always by a click at a button.
It’s not the job of a WM do same since it’s not a DE. Hence after a few web searches. The solution below worked for me. Since I manage my login, WM and DE choice with .xinitrc all I did was to add the following lines to my .xinitrc
export DESKTOP_SESSION="gnome"
export DE="gnome"
I hope this helps!
Reference: Reddit