HELP!!!! Pixel No Valid Slot To Boot :(

Moving boot nvme drive to different slot boot slot Supports up to two externally accessible 7mm hot-swap drives for operating system boot functions Rear: Up to 10x PCIe slots, plus a slot dedicated to the OCP boot slot Hi fellow OP6T users, is there a way to change the boot slot for example from _a to _b within the fastboot mode? I read something about a

booty bay slot The advanced PCI-E Steel Slot packed with solid cover that prevent any signal interference with graphics cards *Supports NVMe SSD as boot disks