I am using U55N&U50C, and vivado 2020.1.1.
the board was added in "Vivado Design Suite - HLx Editions Update 1":
but not listed in any of the dialogs.
How to add them to the project?
Welcome to the Xilinx Forums!
The U50C will need to be handled offline, I have sent you a PM to address. The U55N collateral is accessed via the U55N EA lounge, access can be requested here:https://www.xilinx.com/member/u55n.html