https://www.scmp.com/news/china/science/article/3308662/chinas-weather-modification-test-cup-cloud-seed-makes-30-swimming-pools-rain

Chinese drones released silver iodide into the atmosphere as smoke. Then it rained. China has publicly admitted to cloud seeding with silver iodide for many years. This is not new.

The American company GE (General Electric) applied for a patent related to this technology in 1948.

General Electric Company scientists Irving Langmuir and Vincent Schaefer modified clouds by "seeding" them with dry ice pellets. Not long afterward Bernard Vonnegut, a co-worker, demonstrated that a smoke of silver iodide crystals would accomplish the same result. This was the beginning of the modern American history of weather and climate modification through cloud seeding.

source: National Science Foundation

National Geographic published an article about weather modification, saying:

During the Vietnam War, the U.S. military even tried to swamp the Ho Chi Minh Trail by producing torrential rains.

The US military began spraying silver iodide decades ago. At least the Chinese government publicly admits to doing the same.