Can i update my iphone 5S to ios 14.8

Sorry no. See why in this support article (bearing in mind that iOS 12.5.4 is not affected by security problems corrected by iOS 14.8):

It is not compatible.

It can be updated to iOS 12.5.4.

No. It's not capable of 13 or above.

(204816)

No, you cannot update your 5S as there is no need. This update only pertains to iOS 13 and 14, which your phone cannot run.

At least, we all agree!

👍

Giulio 🇮🇹

You are welcome.