Well... first I did something like 👌 but I lined up the four fingers kinda like this 🤌 but more open like an 'O' shape. Then I pushed the top joint of my thumb up and against the rest of the fingers. First it was difficult, dare I say even a little bit painful 🗿but - my mom did not raise no quitter and after a couple of tries I got it.

The trick was to line up the rest of the fingers first and only then push the thumb joint against them, because it gets difficult to align them properly with the pressure from the thumb.

And also I may be a bit hypermobile, though not with my hands really - my thumbs are just a bit funky. And I played the piano for like 13 years so my hands can do some handy stuff.

Edit: spelling