It's a JFT 6090 from Amazon. I got it from a guy who bought it new but never used it. He said he didn't have a manual. https://www.amazon.com/dp/B014REYVRM/ref=cm_sw_r_cp_apa_glt_fabc_11JJDBPZ2TNKD08FZV2WWelcome to the forum! What instructions are you wanting (specifically)? Got any other info on your machine and the controller? Is it new or did you purchase this used?
Try here: Download - China Mini CNC Routers, CNC Engraving Machine & CO2 Laser Engraving Machine Manufacturer Supplier.
E-stop is not wired directly to the spindle, but instead to an input pin on the control card. Most Chinese machines run Mach3 and can control the speed and start/stop of the spindle from the computer.FYI if the spindle driver is not wired in to the e-stop you might want to consider doing that. Also many spindle controllers have a 5? volt input to start the spindle and run it without using the front panel another nice feature not usually wired into the Chinese machines. I changed out my water cooled spindle for an air cooled version so I did not have to incorporate switches to be sure the water is flowing and to shut down the spindle if their were water flow problems