where do you put the chapter 5 egg

The Chapter 5 egg appears to be in the hidden tree room at the end of the wheat-field puzzle route: go right from the Cliffside Shop, clear the wheat by repeating the dash section until a balloon appears, follow it into the dog/flower puzzle, then take the newly opened left path and interact with the hidden man behind the tree to get the Egg.

Route

• Start by heading right from the Cliffside Shop.

• Work through the wheat field until the repeating patch triggers the balloon.

• Follow the balloon into the flower-and-dog room, complete that puzzle, and proceed left into the secret tree room.

• Talk to the hidden man behind the tree to receive the Egg.

Small warning

Do not leave that room before taking the Egg, because one guide notes you may need to reload your save to get back in.

TL;DR

The Egg is in the secret tree room after the wheat-field balloon route , not in the shop area itself.