I play in my switch, I can't even open the inventory in the air, is there something wrong with my game? or it can't be done on switch?

Inventory drops are patched on 1.4.3.2 (the version switch and other consoles are locked to), so you can no longer open inventory in midair. You can, however, open inventory the physics frame (1/50th of a second) you leave a ledge - this is used as much as possible in Current Patch NMG runs - you can see in this run what it looks like both to fail and get right:

Oh, thank you, I didn't know that it was patched, so the pc speedruns are done in previous versions then?

most speedruns are done in the patch 1.2.2.1, when inventory drops were still a thing along with a lot of other mechanics that were later patched.

Interesting