(KVM 1 GPU) Screen goes black after following tutorial

Hello! I have been following this tutorial

So basically it makes so I do not need to use 2 gpus to run a gaming vm because I do not have 2 gpu and only one.
The problem: When I launch the vm (I use virt manager) the screen goes black and I can hear window 10 in the vm I just cant see the screen.
Here are my specs:
GTX 1060 6gb
Ryzen 5600x
Prime B550M-A Motheboard

Thank you in advance for your help!