Which Embassy should I go to?

Good morning, I am looking to work in China as English Teacher, according to the recruiter I need 2 documents authenticated via Chinese Embassy.
My problem is, My Bachelors Degree is from PR(Certified by the Department of state in Puerto Rico) and my certified criminal background check is from North Carolina where I have lived for the last 2 years. I’m confused as to which Embassy should I send my documents to Washington D.C. or Houston? Do I have to be there in person?