Missing one stamp, help figuring out which?

[bucketsjen]

I'm missing one stamp and can't seem to figure out which one. I watched the video (https://youtu.be/BwH0HbvAPvw?si=SAplQtEr63hwbbGQ) and would swear I got all of those, I'm trying to avoid having to play the entire game over again from the beginning just to find one stamp. If anyone can let me know the area where you get this one, that would be AMAZING.

It's the leftmost stamp on the third row.

[bucketsjen]

Pic w/missing stamp:

https://imgur.com/a/emPdqmP

[ValeConPan]

If I'm not mistaken, I think I know which one it is, but I have some bad news for you. The stamp you are looking for can only be obtained when you help the tortoise, in fact, before that. When you help this tortoise, you go to an island that has a giant machine, with which you will move a wooden board in order to free the tortoise. It is precisely on that island where the last stamp is, which is inaccessible after helping the tortoise. I tried to find alternative paths, but they required impossible jumps, so I had to play the game again, but only until the first mission.