KiCAD: addting a micro via to a footprint
Sorry but kicad footprints don't handle embedded vias.
You'll have to do with THT pad if possible, for full vias. If the requirement isn't actually a full via (like a blind or buried) you simply can't do that.
Reason: kicad footprints lives outside the board, in the libraries; they don't know the inner layers. In fact the only options available are only top, only bottom, or all the layers.