Hy ,I need to update my ios 12.5.7

If your phone is still running iOS 12.5.7, odds are overwhelming that it is an iPhone 5s, 6, or 6 Plus. Those phones cannot update to iOS 13 or beyond. They lack the hardware to do so. Time for a new phone.

It is not possible to update iOS 12.5.7. Your phone is way too old.

Time for a new phone. Make sure that it will at least run iOS 26.