How can I backup my retail Pokemon Omega Ruby save?

I have a physical copy of Pokemon.
My N3DS is on sysnand 9.0 and emunand 10.6
I am using a gateway card.

I tried all the save managers but the .cia only open on gateway mode, not classic mode.
It will only read my retail cart on classic mode, not gateway mode.

I want to back up the save.

What can I do?