Configuration of Active Direcotry remote Access Gateway Windows server 2019

I have a Windows server 2019 Data Center edition running VM for publicclients. I need to configure the Remote Access gaeway to allow client connecto RDS to their virtualmachines. the macines are on my domain but I want them to be able to connect using RDS client with my RDS gateway parameters.

I had istalled teh SSl for the payment gateway but itis not allowing remote access.

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