In order to connect your extender through wps option, for that we need to follow some steps:-
(in case if you don't have any wps button on router itself)
>first of all, connect your computer with the router's network
>then go to the web interface of the router
>now go to the wireless settings of the router and then go to advanced settings
>there you will find wps software button
(Note:- Different routers have different web interface, so you need to find wps option there)
>now press and hold the wps button from the extender for atleast 3 seconds and within 2 minutes press and hold the wps button from the web interface of the router once.
and then wait for the lights on extender to get stable
or you can check the connected devices under the router, if you see your extender there, it means its connected.