how to tell how many nvme drive slots a motherboard has?

I just installed a new ssd card on to my pc and its not showing m 2 ssd motherboard slot expansion slot is the specification for on-board internal expansion cards on a motherboard Intel first introduced m2 slot pc This video explains how to select which slot to use on a motherboard for the best

m2 pcie slot I'm upgrading one of the 1TB drives to a 2TB I will use the MSI Expander on my Creator X299 motherboard to install the new drive so I can