1)Before skin weight paint but after parenting mesh to armature you need to scale both armature and the model by 100 → apply scale and then scale it down 0.01 without applying transform.(This is needed for the proper bone scale in unreal engine)
2)If your model is facing -y axis(it’s looking at you when you press 1 in blender)
I’ve tried different options and found that these work well. In case that image didn’t upload:
in fbx export settings:
in ‘transform’ don’t change anything(make sure that forward is ‘-Y forward’, up is ‘Z up’)
in ‘armature’ primary bone is Z Axis and secondary is X axis.
With these settings I got 0 rotation on my ‘root bone’ in unreal engine after export
Otherwise with regular settings it always adds 90 degrees on X-axis on root bone
I didn’t change anything in unreal import settings
May be this tutorial is not needed but I hope that it might help