Are you sure its finished?? Have you set up user accounts?
One problem that can happen is instead of restarting and making you set up new users, the install will break and not restart from the drive you installed it on. This leaves windows in a half installed state and completely useless.
Is this a brand new PC? If so, the bios should be set up in such a way it should just boot off the USB and you shouldn't need to change any settings.
Something isn't right with your set up
BIOS manual -
https://dlcdnets.asus.com/pub/ASUS/...ME_PRO_TUF_GAMING_X570_Series_BIOS_EM_WEB.pdf
Your bios has an option called Boot override, its what I would use if you want to boot off USB
IS the drive you want to install win 10 on the 1st item in boot order? technically there shouldn't be anything there yet since its not working, but it may. leave whatever is there, as is. If USB is first choice, take it out. It shouldn't be in boot order.
On the boot tab in the advanced view, scroll down to Boot Override
If the USB is in PC, this menu should allow you to boot from it one time, and then on every other boot, it goes back to defaults.
put USB in PC
start PC and go into bios
go to Boot tab and choose Boot Override
Pick USB from list and PC will restart and run USB.
hopefully this will let windows actually finish.