Nighthawk X4S AC2200 R7500-100aus not connecting to netgear router

My Wifi extender is not connecting to the internet nor is my Net gear nighthawk AC1900 recognizing it - trying to mesh the internet- reset to factory setting multiple times, power light blue - wps light blue - 5g blue- but router does not show it connected.  Need to reset so I can see both - tried using the mywifiext.net - to no avail - saying I am not connected to the internet.  Extender does not show up on my phone as a seperate IP address... tried using IP short cut - does not work... NEED HELP!!!! I know there has to be a way to fix.  No way to attach via ethernet only via wifi.