In order to make the object appear in the game correctly, you need to prepare it.
Forward axis: X+
Up axis: Z+
Units: Centimeters
Make sure the model is in the center of your scene (0,0,0 coordinates).
<aside> 💡 Flat shading is recommended so that the model fits well into the game visual design.
How to apply flat shading in Blender </aside>
FBX export from Blender