undefined reference to `FlightSample::FlightSample(DJI::OSDK::Vehicle*)'

Please help me in linking what is missing when compilint only flight-control.
Cmake works but when i compile i get the error : undefined reference to `FlightSample::FlightSample(DJI::OSDK::Vehicle*)'

Could you please let me know what to add to CMakeLists.txt to have it working?

Please DO NOT link me to a useless github or forum answer, i already went troygh all of them and didn't find an answer.