Upstream in Nginx Proxy Manager

[AliMehraji]

Is there any way to add and use the upstream?
I've set upstream in custom/http_top.conf but when I'm using the upstream name in UI, the proxy host goes offline, think missed something! or do I need to map it to the $server?

upstream backend {
  server 192.168.0.111;
  server 192.168.0.112;
  server 192.168.0.113;
}

[likelios]

Yes there is some description here
but how exactly to do this no!

/data/nginx/custom/stream.conf

Therefore, I ask the respected developer to look towards resolving this issue.