Your problem now is selling books, not selling authorization. There is no problem of finding a copyright agent, and your book has been published, and your copyright agency should have been owned by the publishing house. Your problem is selling books. In principle, there are two methods. First, it is issued by local book publishing houses and Xinhua Bookstore, usually by publishing houses. I wonder how your contract with the publishing house is determined. Secondly, you can go to the bookstore with the purchase order of your book, and negotiate with the bookstore and website to sell or underwrite the book at the lowest discount you can accept.