This is the part where I see many of my students messing up.
When I teach this part I always say “arm under the groin area” not “hand under the groin area”.
You should go deep with your arm under the groin area and hook the groins with your elbow, you will have a strong and solid grip this way.
If you just grip with your hand and fingers, your hold won’t be that strong and you won’t be able to lift your whole opponent’s body.
It could work if your opponent is lighter, but if they are heavy you will have trouble lifting them up with just your hand and fingers.