I have a non-online source that says quercetin good to take against allergies. My reference suggests 300-600 mg/day. This is for allergies, peptic ulcer disease, and chronic sinusitis/rhinitis.
The book is called "The Nutraceutical Revolution" by Richard Firshein, D.O. Riverhead books, New York: 1998 pp. 230-241.
I have no idea if this will help a particular person or if it is a good idea to do this. I am not a doctor. You probably need to do your own research. However, this is the same book that gave me the idea to take NAC against COVID before it was popular.
I am sharing this as the FDA has made it plain they want you sick in a hurry and no OTC remedies to help. A lot of people have allergies this time of the year in North America.