I need to update my iPhone 5s

Hello ~ Since your iPhone 5s can only be updated to iOS 12.5.7 it lacks the needed hardware to run anything higher. Most new apps require a higher operating system to download and use . Unfortunately you need an iPhone 7 or higher to run iOS 15. You need to consider a new iPhone. If you consider a security hand device please take the time to read these links so you can make an informed decision by clicking on below…

Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Also:

The All Too Common SAD Reality of Buying a Used iPad/iPhone

Also your new choices…

Apple Store Online - Apple

~Katana-San-