Problems with UPnP

Linux newbie here. Having trouble trying to Port forward with NC-portfoward Upnp on my Router (netgear r6100). when i disabled UPnP I got a error and having it enabled and i dont know how to port forward (I do it’s just im having problems with it) How do i port forward with a netgear modem?.
I Saw something about changing ports by accessing Apache files and i dont know how to do that.

Could you please describe in detail what you would like to achieve? Do you want to reach your Nextcloud server from the Internet?
In that case you should use the web interface (or management port) of the router and look for Port forwarding options. The idea there is to forward specific ports to the Nextcloud server.

Let’s assume the following:

Nextcloud server IP = 192.168.1.99
Nextcloud Ports = 80 and 443

Router Web Interface = 443

Best Port Forwarding would be:
Port 80 to 192.168.1.99:80
Port 443 to 192.168.1.99:443

However while Port 443 is in use by the routers web interface, there are two options:

  1. use a different port forwarding:
    Port 8443 to 192.168.1.99:443
  2. change the port for the web interface of the router in its configuration pane. For example the router is then configured via https://192.168.1.1:5443 instead of https://192.168.1.1:443 (just an example)

I Want to Use my Nextcloud to use from school and other places outside my home.
My ISP Has Blocked Ports 80 and 443.
No-IP Is saying I could Port forward to port 80 and 443.
So I slightly Fix the port forwarding problem the only problem I Have at the moment is the ports.