It is an easy way for a Linksys WiFI Extender Setup to extend the networks. Just see if the router is compatible or not with the main extender.

First, connect the linksys extender to the outlet of the electricity. Now synchronize your home network through the Linksys extender. Once your main router gets enabled to the WPS setting button. Hold the button for a minimum of ten seconds. The extender will automatically verify the network’s signal. If the LED light blinks blue it means the connection is successful. As a result, change the settings of your extender. The SSID of your network is the same as your extender’s network.

The host network's password is the same as the network name so enjoy the connection now. However, if you are not able to connect to the WPS button, the WPS button is disabled on the default ISP gateway. Check whether it is able to be configured or not. Keep the metallic things away from the extender and the existing router to make it work properly. As the network quality won't be consistent. Check if the extender is near the location of the router to cut off the interface.