There are the two flaps which have the marks you wrote.
Backside
There are two pockets on backside. (It is not the place where you wrote the mark.)
Insert the green flap which has the mark to the pocket of sky blue.
When inserted it, the mark is in the pocket, and can't see it.
Add the third part and insert the sky blue flap to the yellow pocket.
Can't see the mark of flap.
Insert the yellow flap to the green pocket.
Can't see the mark of flap. The three parts got together.
Add the fourth part and insert the green flap to the orange pocket.