My iPod is not up to date is stuck on 12.0 version can you assist?

Version 12.0 does not sound like an iPod Classic. Perhaps you mean an iPod Touch.

Two things you can do:

• • correctly identify which iPod you have; go to Identify your iPod model - Apple Support
  • if it is an iPod Touch, you need to also identify which generation it is (which you should also be able to do on the linked page above)

If you have an iPod Touch, then the last two generations of it are as follows:

• • a 6th generation iPod Touch, which cannot be updated to iOS 13. On the day of writing, the latest version for this model is iOS 12.5.7 - available from 23rd January 2023
  • a 7th generation iPod Touch, which cannot be updated to iOS 16. On the day of writing this, the latest version is iOS 15.7.4 - available from 23rd March 2023

If you do have an iPod Classic, it is almost certainly up to date as it does not use the same operating system as the iPod Touch. The two more recent models of Classic will have firmware listed as either:

• • 1.1.2
  • 2.0.5

If memory serves me, it states Version 1.1.2 or Version 2.0.5 in the iPod's settings/about menu.