Access 5G Internet Gateway (UWB) Admin Portal using SSL?

Hi -

I have the 5G Home Internet Gateway (UWB, the bigger one) and wondering if there is a way to make the admin portal access SSL enabled?

I tried and port 443 is opened with a self-signed cert from Taiwan (Common Name: JNR350). Downloaded, installed, and trusting it does not allow me to connect to the SSL port (the connection was dropped). From the router's log, it seems it was looking for a client cert for authentication.

All I want is to access the router's admin portal using SSL instead of sending the admin password in plaintext.

Thanks for the help!