@Richadev 

NAT Type determines how your device is connected to the internet and affects your ability to communicate with other devices and services. NAT Type 3 is the most restricted NAT type. It can limit your ability to connect with other players in online gaming or use certain network services.

To address NAT Type 3, you could try the following steps:

1.Access your router's web interface, go to Advanced->NAT Forwarding->UPNP page and make sure UPNP is enabled.

2.Enable DMZ for the device with NAT Type 3

3.Check the router WAN IP address on Advanced->Network->Status page, if it is not a public IP and there is a Modem/Router combo device in front of the TP-Link router, please change your Modem/Router combo device into bridge mode or follow this guide to configure the TP-Link router as an access point to avoid double NATs: How to configure the TP-Link wireless router as Access Point

If the problem still exists after the above steps, please let us know the detailed topology of your network and result of the above troubleshooting steps.