Please guide me about Let’s Encrypt HTTPS for Openvpn access server

[systemD2540]

Hi ,im new here I have installed openvpn access server already yeah, This work for me
But When i got to web "Red warning SSL Https" I have to follow the instructions from google all
not anymore is work openvpn as 2.5.2

So i need someone teach me and i want to know more how i change client login to > domain.com:943 > to new address > vpn.domain.com
and domain:943/admin > to new fresh > vpn.domain.com/admin or change hidden on

I'm useing Centos 7 for VPS and now domain setting already

Please help thank for topic

[systemD2540]

anybody answer ?