Missing driver for extruder control?

A friend of mine who also bought a printer from you tells me that I am missing a driver for the extruder controller on my ramp. Is this something that is typically included on a ramp or extruder purchase from you? Or did I neglect to order it?

Pic with ramp and 3 drivers is board I received. Pic with 4 drivers on board is what ffriend received when Orduring from you.

Thank you

You need 4 drivers if you want an extruder. The kit comes with three for the cnc. Sorry I tried to include this information on any page that references buying 3D printer parts.