Install of Nvidia card after installing qubves with onboard graphics

I have a qubes install which works (on a 1080p monitor at least) and I’m trying to install an Nvidia 2070 card. Base hardware is a Dell XPS. The initial boot, I don’t get the Dell splash screen, the first message that appears is
"Welcome to GRUB!

error: file `/EFI/qubes/fonts/unicode.pf2’ not found."

Then the screen just goes black and produces no more video output.

Any ideas how I can get this? Do I need to install nvidia drivers before installing the card? Anything to point me in the right direction will be gratefully recieved.

I am trying to install this card as it fails to boot on a 4K monitor but I’ll create a new thread for that as the issue is different