Good Question! How did the US military know that the balloons came from China in the first place?

Air balloon is a very old and ineffective method for surveillance. Many countries not limited to China possess this old tool. Even the US military launched hundreds of thousands of balloons into the sky in the past decades.

Thus, how did the US military know that the balloons came from China in the first place?

https://t.me/stewpeters/20443

I guess this is how they knew the spy balloon came from china.