That part in the picture goes into PCIE slot.
Your board has PCIE x1 slot (small size black color). Use that for graphics card with PCIE x1 riser cable.
Note - PCIE slot on the riser cable is with open end. It's possible to attach PCIE x16 graphics card to it.
No. That is not a PCI to PCIe adapter, that's a PCIe x8 to PCIe x16 adapter. And you will likely have a bad time with a correct adapter; it doesn't increase the bandwidth and PCI's maximum bandwidth is dwarfed by even the first generation of PCIe, something like 15 years ago now.
And here's why this is a scam, based on the assumption this is a PCIe x16 to PCI adapter
Reducing a card that would at the minimum require 4GB/sec of bandwidth down to 133MB/sec sounds like a great time.
PCI can only supply a maximum of 25W. x16 cards are expected to draw up to 75W from the slot.
Maybe this would make more sense if it was really a PCIe x1 to PCI, because at least the power requirement would be met. But you're still going from at the minimum 250 MB/sec down to 133MB/sec. I honestly don't see any application where using this would make sense where you couldn't just get a PCI card instead.