@Ralph5226 

Welcome to the community!

From what I can tell, that router supports 2.4 GHz, 5 GHz, and 6 GHz Wi-Fi connectivity. The RE750C supports 2.4 GHz and 5 GHz Wi-Fi range extension.

If your Spectrum router doesn't have a WPS button, you can use the Web UI setup or Tether app setup options for the RE750C, as outlined in Methods 2 and 3 in the RE750C's Quick Installation Guide.

If the RE750C was connected to another router previously, you'll need to reset the extender first before pairing it with your new router.