My uncle asked me to look after the booth, but what should I tell him if he doesn't want to go?

If your uncle is that kind of overbearing person, then you should tell your parents first that he is your uncle, not your parents. Even if he is an elder, he has no right to boss you around. You can choose to refuse.

Make it clear to your parents that you need to see a doctor for rhinitis now. If your parents tell your uncle about it directly, I believe it will be more powerful to talk to your peers, so that you won't offend him, and you don't have to communicate with him directly, which will make it easier to solve the problem.

But if your parents are towards your uncle, after you tell your parents the reason, you can tell him directly and refuse him. If he treats you like an elder, you lie in bed. "I'm not going, you can do whatever you like."

With the refusal, I'm sure he won't look for you again. Again, he didn't give birth to you or raise you, so he has no right to order you to do anything. He is willing to tell others what is his business. He has a long mouth, so we have no right to shut him up.

However, as he said, there is no need to work for him any more. Let him end up with a good mouth and a good figure. Why not do it? Just hold your breath and work for him later. Isn't that hard for yourself?