How to correctly position the thumb while playing piano?

So, I was just wondering, how do you correctly position the thumb while playing piano?
I have been told, that to play piano correctly and most efficiently, you have to play with the tip of your fingers. But is that also the case for your thumb?

Seeing as your hand is as it is, I believe a lot people will naturally use their thumb in a less efficient way. I think I might even do that myself too.

What I mean by less efficient is that I believe I “tilt” my thumb slightly. So instead of hitting the keys with the “tip” of my thumb, I probably hit it a bit more with the side of my thumb (I am not quite sure how to explain it, I hope someone gets it).