Start with the basics, do you see your Nvidia GPU pop up when using vulkaninfo --summary?
If it doesn’t pop up, verify that you have the correct vulkan ICD files in: $ ls /usr/share/vulkan/icd.d/
There you should have nvidia_icd.json, nvidia_layers.json. If that’s missing, you’re missing the nvidia-utils part of the driver.
If they are there, but it still don’t show in your vulkaninfo sumary, you could try to load the nvidia driver manually; modprobe nvidia, also check the kernel logs journalctl -k or dmesg and search for nvidia to see whether the driver got loaded correctly?