This page from Kogger Tech should provide the info.
It has been some years since I did this myself. With an enhanced module. Some ideas that leaps to my mind:
Double check that Rx Kogger goes to TX pixhawk and vide versa.
Double check that units have common ground.
The pixhawk may not output 5V from the serial port. Maybe use a separate bec for the + wire.
See to that all parameters are correctly set. Also that the frame type is set to boat. That’s needed (was needed at least) to support reading of nmea input sentences.
I vaguely remember I had to set some settings in the Kogger app for this to work. And that I also had some struggle before it started to work.