Ibooks Preview does not see iPad - everything updated

Cannot Preview my iBooks Author project on connected iPad.

Preview drop-down does not show connected iPad.

powerbook OS 10.7.5

iPad air iOS 12

lightning cable by Apple

Shut down and restarted both devices.

Still nothing in Preview drop-down.

iTunes does see ipad.

Have explored web for post 2012 threads.

please help

Thank you.