Please follow these steps:
- Try to restart the Tplink router(Turn it Off and Turn it On)
- Try to use a different browser on your device
- make sure you are entering the correct web address(IP address is 192.168.0.1 or https://tplinkwifi.net)
- Reset the router and reconfigure it again.
If this doesnt help u then revert back so that we can help u in a better way.