If the router is configured correctly the WPS option is disabled. You should not use that feature, you need configure your repeater manually with the ssid and password.
If you have one of the really stupid repeaters that have no other way to set them you are going to have to make sure it is enable in the router. Doing that though means your network is easily hacked into.
WPS has been compromised for years and there is no fix so they should have removed the feature.