User Guide - Using AWS private hosted zones with OpenVPN Cloud
There are two options for properly configuring the OpenVPN Cloud service to work with your AWS private hosted zone. For both options, you must first reconfigure your OpenVPN Cloud DNS servers to use the IP address of the Amazon-provided DNS servers for your VPC, which is the IP address at the base of the VPC network range "plus two." For example, if the CIDR range for your VPC is 10.0.0.0/16, the IP address of the DNS server is 10.0.0.2.
After configuring your OpenVPN Cloud DNS servers, you can then either: