well a couple things I see are when you export from blender pick ‘face’ in geometries smoothing… and when you import choose ‘import normals’ and I also tick ‘use toa reference pose’… as for ‘bone transform’ i’m not really sure… the youtube is from like 2015, maybe find a more up to date one, there are lots of them… for an initial import you leave the armature empty and for subsequent animations you need to pick the armature…