is writing $definebone needed in a qc to not have bones be fucked up in game

ive been trying to make a player model without a tutorial for some time specifically no tutorial with that r6 roblox model tutorial for my own custom models and for some reason in game the bones are broken and have weird pivots and movements while in blender its normal is it needed to write $definebone in the qc file to fix this cuz i moved the bones in blender using the edit mode and added my own bones