How do I use WPS to set up a network printer

We have an old wireless printer that doesn't have a screen, only a WPS button for wireless setup. There is no WPS on the T-Mobile gateways, so we used to work around.

Found an old wireless router sitting in storage that has WPS button. Programmed the old router with the same Wi-Fi name and password as the T-Mobile Gateway. Set up the printer to the old router using the WPS buttons on both. Then unplug the old router. The printer will automatically connect with the T-Mobile Gateway in the future.