XPLMLoadFMSFlightPlan

XPLM_API void       XPLMLoadFMSFlightPlan(
                         int                  inDevice,
                         const char *         inBuffer,
                         unsigned int         inBufferLen);

Loads an X-Plane 11 and later formatted flightplan from the buffer into the FMS or GPS, including instrument procedures. Use device index 0 for the pilot-side and device index 1 for the co-pilot side unit.