Issue with "missing operating system" when booting from USB to install dual boot

Hey all, first time post, so if this has been answered previously, I apologize for the repost.

I just set up my USB with the full 6gb Mojave with unibeast, I copied over multibeast on the USB as well as clover. Figuring I had it all good to go, I partitioned off 500gb of one of my 2 SSDs to do the dual boot and rebooted my HP 870 omen to the usb. I am then greeted with the above message. In the BIOS, I believe I have the settings correct, and it may be more of an issue with the files on the USB.

Can anyone help? Thanks in advance!