Can I courier my China Z Visa Application back to Singapore if I do not want to leave China?

Hi there,

I am a Singaporean living and working in China. I overstayed for over 30days on my last Z visa which expired on June 25th and paid a RMB 5000 fine to exit China. I am now back in China using my 15 day Visa Free entry. I need to re apply for a new Z visa and heard that I have to go back to Singapore to get it, as I do not have a HK ID to have it processed in HK. Please advise if its possible to courier my passport to Singapore for processing. If possible, please let me know the procedure, timeline (I can only stay for 15 days at a time) and cost. If not, what other alternative ways do I have if I cannot take time off to fly back to SG.

Thank you very much!
Deb