How do I reconfigure my router to use WPA2/WPA3? I have a MacBook Air, Monterey system.

How you change security settings on a router varies by brand/model. If you don't have instructions, do an internet search for your router brand/model or if the router was supplied by your Internet service provider, check their website or customer support.

Also see: Recommended settings for Wi-Fi routers and access points - Apple Support