Is there a way I can use reverse proxy like nginx to proxy the traffic to the Lemmy instance deployed with Ubergeek77 method?

I need the instance to be behind dedicated proxy, like Nginx.

Whenever I try to set up the proxy I get the “Bad Gateway” error or error in the redirect.

If I proxy through CF it works, but I want to use my own dedicated proxy server and I have problems with it. Why CF works and my Nginx proxy does not?