Hello @Adi77 

Which password are you referring to, the password to access the router web interface or the password to connect to the router wifi?

If it is the password to access the router web interface, the default login username and password are both admin/admin, while if you have changed to your own credentials and don't remember it, you will need to reset the router to factory defaults and reconfigure it. Below is the guide to reset the router:

How to reset TP-Link router to factory defaults

Meanwhile, below are some troubleshooting suggestions you may refer to if you cannot access the page:

What should I do if I can’t log into web-based interface of my TP-Link device?

If you are looking for the wireless password, you could follow the guide below:

How to find or change the wireless password on the TP-Link products

I hope these help.