Virtualbox guest additions installation

Brand new to nixos, so I’m sure I’m missing something basic. I installed nixos gnome edition went to /etc/nixos/configuration.nix added this inside the main {} block

virtualisation.virtualbox.guest.enable = true;
virtualisation.virtualbox.guest.x11 = true;

I then ran
sudo nixos-rebuild switch

A few minutes later I assumed the system rebooted as it was at login, but I rebooted again anyway, guest additions are not working and the screen is not resizing appropriately, what am I missing?


I only have this value set:

It sometimes doesn’t resize at the login but after login resizes fine for me.
Rumning in Virtualbox 6.1.

I think it’s specific to the X display, if you use wayland (GNOME can be used with both), it won’t work.