How to implement the correct backup Internet channel for a server that is on the Internet?

Question

Web servers

Hello cheaters!
There are 2 providers in the house, there is a web server that throws my site on the Internet.
The question arose how to make a backup Internet channel for the site?
Suppose theoretically I know how to do it, but the problem is when the Internet switches to a backup channel, the server's IP will change, respectively, the site will not be available.
How is the issue of changing the ip address of the server correctly solved, as in cases of replacing the Internet channel (provider). At least point me in which direction to dig.

Answer 1

The first thing that came to mind was that you need a separate proxy server with a stable Internet connection (that is, any cheap VPS). On it is nginx, which redirects requests to your home server. In emergency situations, change the redirect IP address in nginx to the IP of your web server on the backup channel.
But maybe it's easier to immediately rent a VPS for a web server?