I want to update to iOS 15 but it says I need wifi
I want to update to iOS 15 but is says I need wifi
[Re-Titled by Moderator]
iPhone 6s, iOS 12
Question marked as
Yes you need Wi-Fi.
But you can also do the update via PC, see this Apple article: Update software on iPhone, iPad or iPod touch in iTunes on PC
https://support.apple.com/en-gb/guide/itunes/itns3235/windows
If you have a Mac see this Apple article: Update your iPhone, iPad, or iPod touch with the Finder
https://support.apple.com/en-us/HT212185
FYI: You need about 6 GB device storage.