What do say when someone says “You don’t look autistic”?

Hello,

I know this has probably been posted 100 times before so I apologise if it’s becoming tiresome.

I’m 33 and Level 2 Autistic. I don’t quite understand the question as, for me, there’s no stigma attached to how an autistic person should look? Anyway, it’s getting boring and I’m getting irate lol so I’m searching for some answers when getting asked the question.