How to fix weak wi-fi security settings
How do I fix weak wi-fi security settings on my iPhone
Question marked as
Top-ranking reply
You need to increase security level in the Router to at least WPA2. if your router cannot do that then you have the choice to ignore the warning or get a newer router. You are no weaker than you were before you upgraded to iOS14 when the warnings were added.
Perhaps this link will help...
Recommended settings for Wi-Fi routers and access points - Apple Support