If China has it, you can buy it all, that is, get the patent right, so that no one in China can use it except you, unless you agree? ;
You can also apply for an exclusive patent license, which no one can use except you and domestic companies.
Or apply for a general license, you can use the patent, but others who have signed a general license with domestic companies can also use it;
If you want to buy out, it is recommended to sign a patent transfer contract with a domestic company.