mark partition as not mountable

Hello, I just hit a brick wall here, i made a usb enclosore bootable with Ventoy (Asus Rog Strix Arion case with a samsung 970 evo 1TB ssd inside), Ventoy creates 2 partitions, 1 for ISO files or other data to be copied and a 32MB partition for boot, the problem is that i cannot make the 32mb...