Delta snorlax

Hi, im just wondering if theres any way to get my delta Snorlax to learn yawn.

Delta Snorlax (Pokémon) - The Pokemon Insurgence Wiki by prior evolution munchlax gets yawn at 41 so if you didnt get it and you evolved it its gone, maybe u can get it with a heart scale but i doubt it

Thanks for he help bro. I appreciate it