FBX export deforming mesh

General FBX question: does anyone know how to export deforming meshes as FBX from blender?
And that’s NOT deforming with an armature.
Deformed to conform to a ground object using shrink-wrap.
Can export them fine & dandy as an alembic, but can’t work out how to get the deformations in an FBX… Any ideas?!?