HOW TO SECURE(SSL/TLS) RDP ACCESS with AWS ACM Private certificate (CA)

We have created Root CA and Subordinate CA in ACM AWS Private Certificate Authority After the status is Active , We can able to export the certificate body and chain from Root and Subordinate CA. Now, I want to install the certificate for RDP connection which is running on EC2 windows OS While taking RDP "The identity of the remote computer cannot be verified" it shows, So how to install AWS ACM private certificate for it? What can i do further to proceed?

https://docs.aws.amazon.com/privateca/latest/userguide/Create-CA-console.html

https://docs.aws.amazon.com/acm/latest/userguide/gs-acm-request-private.html#request-private-console

This step for Machine A where RDP service is running: https://serverfault.com/questions/1044614/windows-10-pro-as-rdp-host-with-ssl-certificate-how

This step for Machine B where you use RDP client to access Machine A: Certificates signed by a private CA are not trusted by default, and ACM does not support any form of validation for them. Consequently, an administrator must take action to install them in your organizations's client trust stores.