software update to 14.8 not available on my ipad
my ipad indicates I have IOS 12.5.4 and there are no updates available?
iPad mini, iOS 12
That message mean that you have an iPad 2nd or 3rd generation, not supporting iOS versions past 12.5.4, because of hardware (CPU/RAM) incompatibilty.
That said, security patches provided with iPadOS 14.8 solve vulnerability problems just for units running iPadOS 13 or later.
Regards
Giulio