Renewal of China Travel Document

My friend's US born baby boy who is residing now in Beijing wants to renew his China Travel Document. My friend & his wife are of PRC nationality, their boy was born in Los Angeles 2 years ago and is a holder of US passport.

Could they come over renew the Travel Document with the Chinese Embassy in Seoul? What about rhe Procedures, documents required & processing time?

There is a saying in China that parents applying to renew travel document have to declare to give away foreign nationality of their kids, is this true?

Rgds/Philip
Email: jakhkogmail.com