Question about Icy Box Card reader 5.25 IB-867-B

The 20-pin USB 3.0 connector on the mainboard is already occupied. In order to connect the ICY Box, I need an additional plug and I think that I can do it with an additional plug-in card (Delock 89315 PCI Express 2x USB 3.0 or i-tec PCE22U3 4x USB 3.0), although the documentation of the two plug-in cards only mentions a 19-pin plug ? Unfortunately, both my internal USB 2.0 plugs are also occupied... Is there a plug-in card that also provides 2 internal USB 2.0 (10-pin) slots? Or is there an intermediate plug so that I can connect these two to the rear panel of my PC, where there are 6 free plugs for external USB 2.0 and 3.0, which I don't need at all?