OpenVPN and certificates


New here and was thinking I wanted to take up the topic of certificates over VPN.

I am using openVPN but I can’t figure out how to have a secure certificate for https. I have installed a Let’s Encrypt certificate on my Synology NAS but that is assigned for my DDNS. When accessing DSM over VPN, I type This results in the web browser saying that the connection is insecure.

I have googled this to see if I can find a solution but I am not extremely tech savvy although I know a few things. Some things just seem very complicated and hard to wrap your head around.

How I understand it is that it should be possible and that you should be able to create a private authentication or certificate of some sort but I don’t completely understand what that is or how it works.

I thought maybe more people have troubles with this so I figured I could ask here.

Thank you all.