Wifi saids weak sercuity

This is indicating that the Wi-Fi network you have connected your iPhone to has a weak security setting. This is just a warning. If you are the owner of this network, then you will need to reconfigure your wireless router to use, as a minimum, WPA2 with AES as the security type.

if it is your wi-fi network, configure the router to use WPA2/WPA3 Personal (AES) security type for the network.