Router as extender or how to extend WiFi

[NBachvarov]

Router as extender or how to extend WiFi
Hi, please give me a tip how to extend WiFi network that is open , but when you connect to open WiFi ,it requires sing in . I tried to use Tplink Ac750 as extender option, I setup it but when I connect to the router wife with my phone I can’t reach this sing in page to connect to internet. It only chow me that router is connected to WiFi network an no internet message. Can you give me a tips is it possible to extend network like this.

[Bruce]

need more info.

what wifi network, home or work?
any reason why it is open, and doesn’t have a password?
and is this sign in page on a web browser?
how does the wireless device connect to the internet, does it have an ethernet cable going to a modem?

what is the hardware involved - give us the make/model of your internet gear; modem, router, extender, etc.