Cross compile on ARM64 (QGroundControl)

Hi, i m Davide a junior software engineer and i m currently working in a company in Italy. I need help to cross compile an open source software from ubuntu amd64 to arm64 platform like raspberry pi 4 /5 or jetson . The repository of the software it s available on github. "QGroundcontrol version v4.4" . I m new in cross compile and i dont know how to start to build this software on arm64. Let me know if you are the right person. Thank in advanced. i think we need like 2 sessions together or 3 idk.