Installing TrueNas onto UGREEN 4800GT. Trouble with NVMe?

I'm trying to flash TrueNas onto an NVMe. Couple of days ago I tried with cheap NVME that I couldn't see in either m2 slot so I've done a return and purchased a Patriot NVMe.

Now I can see this NVMe in the bios but when it comes to the installing it says 'select at least one disc to proceed with the', I click ok and it takes me back to the previous screen where it asked which drive to install on.

what am I doing wrong?