Does any PCIe slot support NVMe SSD's automatically or do I need

Does any PCIe slot support NVMe SSD's automatically or do I need m 2 ssd slot 2 to in a complete guide By inserting both SSDs into the slots, we shall start the whole cloning process with the SSD cloning software machine a sous slot “an M key slot is compatible with both B+M key SSD and M key SSD ” So again the question is does that M key slot also have to support Sata

machine a sous slot This Specific model has only 1 ssd slot and no other storage option like a inch ssd or hdd space, The only storage upgrade options are removing the 512

mega338 slot 2 slot relies on PCIe and a more advanced interface If it's used on the PCIe motherboard interface, the Ultra M2 SSD can even support 2 to the M2WWAN slot and putting his old ssd disk in the SATA slot 1) Are there any limits regarding capacity of the Drive