Chinese visit visa for US nationals living in PNR

Hi,

I am based in PNR and working here for past 1.5 years. I need to go to China on a business trip for 1 week. I am USA national so is it possible to apply for it in Congo/PNR? Do i have to travel to RDC for application or i can just send the passport/ related required documents?

Also how long would the process usually take?

Thanks a lot

Guest