Fujitsu S1500 with insaned

Hello,

I installed insaned on Linux because I would like to use my Fujitsu S1500, that works fine, but unfortunately only "scan" works for me, I would like to have it duplex scanned when it notices that there is a backside and I would like it as PDF.
Can anyone help me there ?
I don't know how to program the button like this, because I have no experience in programming.