RAK2171 TrackIt SDK/HDK Capabilities?

Dear all,
We want to make specialized function to a button which is the so-called function button. To our surprise it cannot be programmed on a higher level, so we want to make some firmware adjustments to this button to behave like this: when we press the button once, send the measured position to the LoRAWAN Gateway ASAP. We would like to make a “caller” button basically, the position being sent to a rover, and the rover would receive it as a waypoint to reach, so it will navigate there, where the tracker is.

How would you start working on this issue?

Every answer is appreciated. Thank you very much.