How to mew where it hides double chin?

Hi, I see people on TikTok and YouTube show their side profile where they have a double chin and once they mew their double chin goes away. I mew and I feel like I’m doing it right but it does not change my side profile at all. I’m very thin but I have a lot of fat under my chin. I think it’s due to having a recessed chin or it could also be genetic. How do I mew to where it hides/gets rid of my double chin?