1. Go to your router's setup page

2. Log in— if you don't know the user name / password, try combinations of admin and root, and even leaving the fields empty, for both username and password. Google your router's make and model to find out how to log in

3. Once you're in, look for a page marked Applications or Virtual Servers or Port Forwarding or UPnP

4. Once there, look for an option for Universal Plug & Play, and enable it

Here are some guides on how to enable UPnP on various popular routers (ignore references to the camera)

You may also need to consult the router firmware compatibility chart and make sure your router's flavor of UPnP is compatible with Jaadu Connect. Note that for the Netgear MR814, the older firmware (v2, not v3) is actually the better choice.