Issue with DL20 Gen11 and Intel e810 2x SFP28 OCP network adapter

[Ico-Developer]

I've got 2x DL20Gen11 and 2x Intel e810 OCP 3.0 Network adapters; same issue with both systems: the networ adapter is not found when plugged into the external OCP slot. No error, Slot is displayed as Empty Slot in device inventory.

Looking at the user guide, I find "External OCP enablement cabling" with parts 63683-001 and P63690-001 - I presume I need those to be able to actually use the external OCP slot? 

If yes: where to order, so far nothing seems to come up wehn looking for these part numbers.