Hello vincentfong,
I see no one has responded to this post yet. So, at this point I would recommend contacting your local Xerox Support Department to speak with a Product Specialist for more assistance. Please call 1-800-821-2797 or 1-800-835-6100.
I tried to print many times from different laptops and iPhones, but it came with this error code 016-756. I can only print by plugging a usb...
Thank you for your help.