Export to unreal

hello

I’m importing from Blender to Unreal and some holes appear in the mesh as in the image below.

What is the correct configuration when exporting from Blender to Unreal via FBX?

image

the message that appears when importing fbx in unreal is this:

Cube_035 has some nearly zero tangents which can create some issues. (Tolerance of 1E-4)
Cube_035 has some nearly zero bi-normals which can create some issues. (Tolerance of 1E-4)

thanks

This also appears:

This also appears:

In this case the message that appears is:

No smoothing group information was found in this FBX scene. Please make sure to enable the ‘Export Smoothing Groups’ option in the FBX Exporter plug-in before exporting the file. Even for tools that don’t support smoothing groups, the FBX Exporter will generate appropriate smoothing data at export-time so that correct vertex normals can be inferred while importing.