@SergSel2006 @Vivaldi
> you can still use HTTP woth this option, but it will display a warning

I know. That's why I'm asking.

> If you can publish your http and https ports, you may be ok to have one FQDN from free DNS and one certificate from Let's Encrypt

I have internal DNS zone served by my router for my LAN, but I'm not planning to publish my internal resources.
I'm also familiar with LE, but this is not my use-case.

> you can install HTTPS Everywhere

Yeah, I know about this extension, but I moved from using it to native Vivaldi feature. The less extensions are installed the better for security.