Launch Google Earth Pro and open your KML/KMZ file. Create a Tour: Locate your path or points in the "Places" panel.
Also install system-wide:
Best for: Professionals (Mining, Engineering). Global Mapper is paid software ($550+), but its video export is flawless. It allows you to set a specific camera angle (oblique vs. vertical) and fly exactly along your KML line at a constant speed. convert kml file to video