Is there a lock symbol (which might look like an unlocked padlock, for a non trusted certificate) to the left of "http(s)" or "ovarit.com" in the address bar? If so, You could start by clicking that, then "Show Certificate", and then "Trust" from the dialog box that comes up with the invalid security certificate in it—at which point You should be able to pick an option that forces Your system to "accept the certificate" i.e., whitelist this site as safe.

If that doesn't work, as stupid as this sounds, is Your clock or calendar off the current date? If so, that can cause some of the security certificates to be future-dated, which will mark them as invalid lol... if this is the problem then just opening up Time & Date and auto-setting the time should fix it.

If neither of those works, then you can go into the "Keychain Access" app and manually dig up the site certificate... lmk if You end up having to try this, and I'll tell You where to find it.

Which version of macOS are you running?