PCIe Slot type Librem 14

I am looking to upgrade the SSD in my Librem 14. What version slot does the Librem 14 have? PCIe 3.0 or 4.0? I am looking to get either the Samsung 970evo or Samsung 980 Pro and with the 980, to take advantage of the speed you need PCIe 4.0.

Thanks!

PCIe 3.0. But PCIe 4.0 disk will work, although at 3.0 speeds.