@marwaniii 

Hello，

The range extender can extend the wifi signal if you know the password of the public wifi. But the distance between public wifi and your range extender can't be too long.

The coverage of the range extender is 10-15 meters so that it can perform well.

Here are 2 links you can refer to log into the web UI of the range extender:

For single band:

https://www.tp-link.com/en/support/faq/698/

For dual-band:

https://www.tp-link.com/en/support/faq/1398/

If you need any further help, Please find the model number at the bottom label of the product, which may begin with TL-xx, RE.xx or Archer xx. Please also find the hardware version of the product, which begins with Ver.xx. 

Have a nice day!