I might be mis-remembering but I thought the older firmwares used to attempt to use upnp to configure the upstream router to forward port 83 however the current ones do not. If I have control of the upstream router it’s not a problem to do the port forwarding manually but it would be nice to be able to at least attempt upnp. Is there a good way to do this?
You can try to use upnpc (needs to install first via opkg).
We found that this upnp does not work well usually and have to remove it. We are seeking another solution (frp) for such situation now.