Had this happen one too many times lol. I usually say “Hello my name is ____” usually gives me time and I don’t think about the name as much. Another technique I use is to say my nickname, I know it’s different for everybody but your not alone. I think the more anxiety you have about it and being put “on the spot” as people are so used to getting a quick response for introductions makes it worse. You got this gotta live with it anyways might as well do what you can.