Wifi

If you're on iOS 12, then you most likely have an iPhone 6 or 6 Plus. You can't update any further than that.

An iPhone 6/6plus can't be updated beyond 12.5.6, it doesn't have the hardware needed to run anything higher.

If you need a higher iOS version, you will have to purchase a newer phone.

atkings Said:

"Wifi: Hello! Have been try to upgrade from iOS 12 to 14 or later! It will always tell me to connect Wi-fi"

-------

Updating an iPhone:

Use a Ethernet, on your computer. See my User Tip:  Update your iPhone Using a Computer - User Tip

You need to be connected to a WiFi network to update your iOS version. Start here: Update your iPhone, iPad, or iPod touch - Apple Support