How do i export a house in blender, to unreal?

Hello all, new to the forums here. Ill keep it brief.


This is a house I have completed for a test run. For some reason It uploads it to unreal as a cube that you can’t walk into. How do i get it to where you can walk through the front door, and other door in the house? I have tried several methods and different file formats to upload this, and it just doesn’t want to seem to upload it as a whole, allowing you to walk around in the house.