HPE ProLiant DL20 Gen10 Plus User Manual page 140

c. Open the riser slot bracket (callouts 1 and 2) and remove the slot blank (callout 3).
Retain the slot blank and the screw for future use.
d. Install the add-in card.
Make sure that the add-in card is seated firmly in the slot.
14. To install the add-in card in the riser slot 2, do the following:
a. Remove the riser slot screw (callout 1) and slot blank (callout 2).
Retain the slot blank and the screw for future use.
b. Install the add-in card.
Make sure that the add-in card is seated firmly in the slot.
Installing the M.2 SATA SSD enablement option 140