The computer uses the Amazon certificate to authenticate the server. If the computer does not already have the Amazon root certificate, it must be imported.
Select Manage computer certificates in the Control panel, or search for cert
Import the certificate under Trusted Root Certification Authority.
Import under Current Machine.
Select the Amazon Root CA 1 certificate file provided by Factbird. It is also available directly from Amazon:
https://docs.aws.amazon.com/iot/latest/developerguide/server-authentication.html
Place the certificate under Trusted Root Certification Authority.