Windows 11 won't install

I bought a Windows 11 USB boot device after getting a new hard drive. Unfortunately it won't install so I checked and it seems some people can install the Windows 11 on the 790 Optiplex probably using rufus but Optiplex is only compatible with Windows 10 not 11. I messed up thought after seeing Windows 11 on the videos for the same computer that is what I should get for my computer. Do I have to return it or can I install it in some why? Rufus needs an empty device not an already existing USB device from Microsoft. I don't want to spend more money but I may have to in order to fix this mistake.
You can have a powerful PC running Windows 10 that cannot be upgraded to W11. I also have such a desktop PC which doesn't meet the requirement of having at least an 8th generation intel cpu. There's no acceptable way past this so try to get a refund for the usb device. If you sell stuff on ebay you could try to resell it. As you don't need one of these to install W11 you may just have to grit your teeth and accept the hit.