nm-tray has the benefit of being Qt instead of GTK (use already loaded libraries, consuming less resources) and lighter than conman. But, it is a little short for more complicated networking like VPN.
To configure a VPN the best way to do it is with in the Menu under :menuselection:`Preferences --> Advanced Network Configuration`. That will open network-manager-gnome you will need also to install the corresponding packages. In case of pptp those will be network-manager-pptp and network-manager-pptp-gnome. The you can follow the configuration instruction for each VPN type.
After the creation, it will appear as a new connection in nm-tray. One thing to consider is that nm-tray does not support password asking, so either you save the password FOR ALL USERS or you will need to connect differently.
nmcli con up id <VPN_name> --ask changing <VPN_name>
with the actual VPN connection name. The other option is to use nm-applet, the "simil" to nm-tray from network-manager.gnome. You can run it from the terminal typing
and you will end up with 2 connection indicators in the tray. The you can connect to the VPN with nm-applet and after the connection is established, you can close nm-applet and the connection will still be present.
If you don't want to run by terminal nm-applet you could change nm-tray for nm-applet. You will need to change the autostart. The easiest form to do this from the GUI is in the Menu going to :menuselection:`Preferences --> LXQt settings --> Session Settings`. There go to the :guilabel:`Autostart` tab. You will see a list with checked and unchecked box, to autostart nm-applet, check :guilabel:`Network` to disable autostart for nm-tary uncheck :guilabel:`nm-tray`.
