How to secure home network routers (Install security certificates)?

[WWGD]

TL;DR

How to secure home network router pages, which by default point to an http://

Hi,
My home network router page is stored at a http:// xxx.xxx.x.xx address, thus not stored securely. As I understand, I must install security ceritificates on them in order to secure them (i.e., encrypt back-forth communication). There are(verified) sites that offer such certificates for free . Has anyone been able to do this, i.e., install security certificates, using run-of-the-mill routers, i.e., rather than fancier corporate ones?

 

[Rive]

You mean, the configuration interface of your router? And the address is the usual 192.168.0.1 or 192.168.1.1 -kind of thing?

As far as I know (had only a very limited number of routers yet) these are not available from 'outside', or - depending on the setting - may be available only from a set address/port, access might be disabled from wifi and so.
In short, the security of this interface is fundamentally different and less demanding compared to pages 'for the wild'.