BIOS needs MBR bootable usb but disk is GPT

I am not understanding what you mean by bootable usb flash partition scheme MBR and bootable usb flash partition scheme GPT.   The SSD should have no partition scheme.

@TAUFAEDITS  Keep it simple by using the Microsoft Media Creation Tool if at all possible. Then boot the device in UEFI mode. Depending on how you set up the flash drive (Microsoft’s tool uses MBR and FAT32), it can be possible to boot the same flash drive in either BIOS or UEFI, and you will see separate boot options for the same flash drive in the F12 one-time boot menu as a result. Make sure you choose the UEFI option. Then in Windows Setup where you choose where to install it, delete every existing partition on the disk where you want to install it until the ONLY entry for that disk is “Unallocated Space”. Make sure you do NOT accidentally delete partitions on completely different disks. Then choose to install Windows to that unallocated space. It will create the necessary partitions automatically.

@ieee488  The OP is referring to the partition layout scheme of the flash drive itself. It sounds like they’re using Rufus based on the descriptions of the options. And that will affect how that flash drive can be booted and therefore what partition layout scheme will be acceptable for installing Windows. It’s not necessarily the case that the target disk is currently empty and uninitialized.