I want my 3rd best friend to be a key speaker at my wedding
What does your 3rd best friend think about that?
I don't think they want to but I wont accept a no.
It is good to choose the guest speakers at your wedding. You should be kind if they have anxiety and don't think they can make a good speech to ask someone else.
He can do the speech if he try.
I'm sure you think that, but you should still not pressure him. People with anxiety will find it difficult to make a speech.