The utility model can only be applied in China National Intellectual Property Administration Patent Office. Of course, you can mail the application documents to the reception office of China National Intellectual Property Administration Patent Office. I don't have to go to Beijing in person.
Supplement: Yes, it can't be used. But this is not the overlord clause, because you can't prove that you invented this thing. Of course, if there is such a dispute, if you can provide strong evidence to prove that this thing has been invented and actually applied before others apply for a patent, then the patent that others have obtained may be invalid.
In fact, there is no intention to force the inventor to spend money to apply. If you don't want to spend money to protect what you invented, you can keep it a secret and don't let others steal your achievements.