How do I find out what version of Dorico I am running on my iPad Air

Dorico version running

Welcome to the forum, @Warrick_Kear

In the App Store.app there is a list of your installed applications and the information about the version number.

Welcome @Warrick_Kear !

The version number is noted on the bottom center of the Hub.

The App Store has a link under your profile to show recent updates which will also show updates that are available.