Add SATA disk to NitroPC

I have a NitroPC with an NVM2 disk and I’d like to add a SATA disk, as it seems supported. Is there any documentation on how to do that and what disks are supported?

I opened the case by removing two screws and removing the top. The top has some kind of rack that seems obviously intended to put a SATA disk. From there, I see on the motherboard a 9-pin connector with a SATA_CONN1 label next to it but it does not look like any SATA connector that I have seen so far. Is it the one to use? With what kind of cable? Also, can that provide power to the disk? I see absolutely nothing looking like a spare power connector.

It that matters, on the motherboard there is a label MNVSUO1 and below VER:C1.

Note: one of the two screws holding the top was loose (turning it either way makes nothing and it won’t go out) and, just above that loose screw, there is some small damage on the case as if someone tried to remove the cover by force with a flat screwdriver, not nice for a new product. It wasn’t easy but I managed to pull the loose screw (it is not magnetic) with tiny pliers, grabbing it using a tiny space between the screw and the case that appears at some point when turning the screw with the screwdriver.

I sent a message asking for support.