@528bos 

Hello, 

1. If you did not change the password before, please find the default password which printed on the bottom label of the actual device, it is 8 digit numbers. 

2. While if you changed it earlier and forgot it, first, you can try to login to the web interface of the router to find the wireless password.

How to login: https://www.tp-link.com/en/faq-712.html

3. Otherwise, we have to reset it and use the default wireless password, and after that, you need to reconfigure the router to make it work.