Epson WorkForce AL-M200DN User Manual page 211

2. Insert the toner cartridge into the cartridge holder, and then turn it clockwise to align to the lock
mark.
Important:
Be sure to secure the toner cartridge firmly before printing. Otherwise, it may cause some defects.
3. Close the toner access cover. Make sure that the cover clicks into place.
AL-M200 Series User's Guide
Maintenance 211