Synology nas and upnp

I install openwrt on dsm with vmm
I got a problem when I try to add the bot from synology Nas to openwrt through the upnp program, the synology Nas device recognizes openwrt
Then I get a message that says

Failed to save all port forwarding rules. Please make sure the following
requirements are met:

  1. UPnP/NatPmP protocol is enabled.
  2. Number of port forwarding rules does not exceed the maximum number allowed on the router.

Not sure that understood you, but probably you need to install miniupnpd and luci-app-upnp and enable it.

Go to Luci / Services / UPnP and check all these:

  • Start UPnP and NAT-PMP service
  • Enable UPnP functionality
  • Enable NAT-PMP functionality

On the same UPnP page in the "Active UPnP Redirects" you'll see a list of forwarded ports

Thanks for answering the questions
I have already downloaded the two files and they are activated
This is the link to the pictures

Basically you need a natpmp client installed on the router and execute a command to forward a port. It will connect with the ISP's miniupnp daemon and open the forwarding. So that upnp is not needed on your router if you can use the fixed port for the forwarding.
But if you want the second forwarding to be made by the upnp the search for cascading .
Here is the firts link which I found, maybe it may be useful