Taking Xiamen airline to Vietnam but stop at HangZhou

Hi,
I plan to go to Vietnam, but planning to take Xiamen airline. My question is if I fly to HangZhou, and I plan to stay there for a few days, then I fly off from Shanghai airport to Vietnam. As I take Xiamen Airline, they will stop at Xiamen first to pick up some passengers before flying off to Vietnam, my question is whether I can still apply for the Visa-free transit when I get off at HangZhou? Thank you.