32u4 based APRS Tracker

Dear all,
i'm a super Rookie, so sorry for the basic question (and for my ugly english).
I'm trying to understand how to connect the radiometrix hx1 to FLORA (based on 32u4 chip), expecially the radiometrix PIN 4. It's a PD4 XCK pin, but on the FLORA there isn't the exact corrispondence. Is it possible to link it to any digital pin? And the PIN 7, is it correct to link it to the Flora pin TX (PD3)?

thank you very much for your time

francesco