How can you do this GT???

How do you do the GT at around :40 sec in this video???

which gt? the one after 40 seconds or the one before it?
on the one right before 40 seconds you go like your gonna land into a trapeze and his brother but you land it over your wrist instead of in front of it.

i meant the one at :43 the grind to GT

If you watch it a few times, you can figure it out. It looks like you just grind then throw the string around the outside of your hand and into the gap or something…

I tried to do the trick before, and i grabbed the slack and went over it from my body, but it didnt work lolz