Ask someone to write and give money.
You can say: hello, I'm glad to answer your question. If you ask someone to write, you can say that I enjoyed seeing your Mo Bao last time. If you are free, I'd be happy to splash ink and write a word for me. You must respect him and his works in front of him. When you ask him for an inscription, show that you are eager to get his works and will cherish them. So he will be more willing!