This option is recommended for small-scale deployments or test scenarios only. After installing RD Gateway, you must manually ...

This option is recommended for small-scale deployments or test scenarios only. After installing RD Gateway, you must manually install the certificate on clients that communicate with this server. This option may not work if the internal common name and the FQDN of the RD Gateway server are different. To correct this issue, use Remote Desktop Gateway Manager to create a new self-signed certificate.