Whenever I import a .fbx model, it deforms and gets 'inverted'. What am I doing wrong?

I made a simple window in Blender and whenever I export and import it into Unreal, it sort of inverts. What am I doing wrong? I have been trying to work it out for about an hour now.
I am relatively new to both of these programs, so pardon the ignorance.

Blender File:

3D Model:

If anyone knows a fix, please let me know.