This is your motherboard from here right?
https://www.msi.com/Motherboard/mpg-z390i-gaming-edge-ac
I think that shows 2 x M.2 and 4 x SATA 6 Gpbs?
https://www.msi.com/Motherboard/support/MPG-Z390I-GAMING-EDGE-AC#down-manual
Well, if it is this one, you get a M.2_1 and another one on the back:
This is getting a tiny bit ironic though, as you’re sort of doing Bob the Builder stuff now. 