What expansion options does the QNAP TS-462T3's PCIe slot support?

Regarding the QNAP: One PCIe Gen 3 x2 slot lets you add a 10GbE network card, a QM2 M.2 card, or a USB 3.2 Gen 2 card. It also supports USB 3.2 external storage. Not bad for a compact unit.