How to I change the mobile WiFi for a more secure setting? WPA to have
How do I change my WiFi to be more secure, to a WPA2 or WPA3?
iPhone XR, iOS 14
See this Apple support article for how to configure your router correctly—>Recommended settings for Wi-Fi routers and access points - Apple Support, specifically the section headed Security. And don't forget to configure your range extenders (if any) also!