An error occurred when trying to install ios15.7.1 on my phone 7

Tomi-rejoice wrote:

i couldn’t install iOS 15.7.1 on my phone

If you have an add-on VPN client app, remove it.

Force a restart, and try the Wi-Fi update again:

… Force restart iPhone - Apple Support

Here are the usual reasons updates fail, and what to do:

… If your iPhone or iPad won't update - Apple Support

If the Wi-Fi update fails and the usual reasons don’t resolve this, use a Mac or Windows computer to update:

… Mac with macOS Catalina or later…

… Mac with macOS Mojave or earlier, or a Windows PC.

If that fails:

… If you can't update or restore your iPhone or iPod touch - Apple Support