In theory yes.
The SD card reader should be detected in the files App, and you can move files and photos from the Files App and the Photos app onto the SD card.
You cannot move Music, Movies, Email, Notes, Apps or Contacts however.
You do need however an iPad running iOS 13.4 or later to support external storage devices.
If you do have an iPad Air 3rd Generation and it's running iOS 12 as your tag line suggests, it would need to be updated to iOS 16 first.
If you actually have an iPad Air 2nd Generation, then it cannot be updated beyond iOS 12.5.7, and cannot directly use external storage devices.