How to flush mount Garmin GT56?

I'm replacing all my old Lowrance stuff with Garmin.My question is...how do I flush mount the GT56 transducer on the transom step. In the picture below, you can see my old Lowrance LSS-1 transducer. I'd like to mount the GT56 in the same way, but I've been stymied thus far. Any advice?

Not sure you can. Garmin customer service is great, I would call them.

because of where the cable comes out you have to mount on vertical surface, get one of these and no holes in transom.

https://www.scheels.com/p/stern-sav...pf6P1L4XKuynckKsn7eyrJV2M-xoCX98QAvD_BwE

or mount to jackplate with one of these.

https://www.garmin.com/en-US/p/147934