how do i update my iphone 5s

To update over the air from the phone all of these requirements must be met:

• You need at least 6 GB of free storage
• You must be connected to a Wi-Fi network (and not a personal hotspot)
• The phone must be charged to at least 50%, and preferably plugged in so it stays above 50% during the update
• The phone must not be in Low Power Mode
• The phone must not be connected through VPN, and it may be necessary to delete any VPN apps and VPN profiles
• The phone cannot be in Airplane mode
• You cannot still have a beta version installed on the phone
• You cannot have a previous version that was downloaded, but not installed - go to Settings/General/iPhone Storage to look; if you find an iOS installer, delete it

If you can't meet all of them you can still update using your computer.

ADDED NOTE: If you have a 5S, are in the US, and your carrier is T-Mobile or AT&T your 5S will no longer work for cellular voice or data, as those carriers have shut down their 3G networks. If your carrier is Verizon the shutdown will be completed at the end of 2022, however, parts of the next have already been decommissioned so you won’t have nationwide coverage.

The maximum version of iOS you can get on an iPhone 5s is iOS 12.5.

Anything above will not work due to the iPhone being simply too old.