There are 2 types of balloons. One can not fly and the other can.
For the one that can not fly, I think we can say "hang the balloon on the door handle by its string"
However, "hang" is often used for things that are pulled down by gravity such as a bunch of keys, a jacket etc.
But, I am not sure if "hang" can be used for things that fly up like a flyable balloon because the balloon is not pulled down by gravity.
Is it correct to say "hang the balloon on the door handle by its string" when that balloon can fly up?