How did the Qing Dynasty recover Ili from Russia?

In the third year of Guangxu (1878), the Qing army regained southern Xinjiang. The Qing Dynasty sent Chonghou to Russia to claim "escrow" Yili. Russia played tricks, extorted more rights, and was forced to sign a contract without authorization, which caused great controversy. The Qing court transferred Ceng Jize to Russia, demanding to change the contract. In the seventh year of Guangxu, the Ili Treaty was signed. China lost 70,000 square kilometers of territory, although it recovered Ili and recovered some benefits slightly. After the Qing government recovered Xinjiang, it recruited refugees, built water conservancy projects and rewarded farming in an attempt to heal the wounds of the long war. Guangxu was established as a province in ten years, which was unified with the mainland administrative system.