Lost Flag Help!

My 5 year old son loves to play Pokopia. He plays a little bit every weekend. He has collected a good amount of Pokemon & has created chaos all over his game...

Here is the problem - he is stuck a 'Put a flag on your home' in the main quest. He has built 1000 boxes (legit boxes everywhere) and I've helped him check every single one.... I think.... to no avail. He does not have a recipe to create a flag. Is there any hope? Is there a way for me to get him the flag?

My wife just completed the Pokecenter in her safe and he broke into tears because he can't find his flag, so I'd say it's going well

Thank you!