Apply for "home return" permit in the U.S?

Hello, am holder of a HK permanent ID card, currently residing in the U.S., want to visit Guangzhou, will have a short 1 day transit in HK. Can I apply for the "home return" permit in the U.S., or failing that, do I have to apply for this permit in-person in HK or can my sister in HK able to obtain this permit for me before my arrival?

Thank you.