@darshmtr
Hello, when you try to access the router via Tether app, you need to type in the login username and password, but not the wireless password. Please check the following info if Tether failed to log in TP-Link device:
1. Make sure it is the correct login username/password (admin/admin in default settings and this might be changed by yourself; if the TP-Link device is bound to a TP-Link ID, please check it as well). The username/password is the same as your login credentials for the web management page.
2. Make sure the TP-Link device is using the latest firmware.
3. Ensure it is in Router or Access Point mode.
4. Reboot the TP-Link device or restart the Tether app.
5. If the username/password is forgotten, please reset the device manually and use the default login credentials (admin/admin).
BTW, you can also login to the router web GUI:
https://www.tp-link.com/support/faq/2215/