TOPIC:

The Standart 380 Motor.
It looks like there is no Motor Mount for a small block in the Partslist of the Instructions.

The m06 is designed for the 540 . No interest to use a 380. If you want low speed you can use a crawler motor. 

As Flo said.

If you want slow speed, 35-55turn crawler motor should do it.

Hackmoto V2 45turn is a good cheap one.

I have not tried it, but maybe Grasshopper motor mount adapter might fit as it`s designeded to use 380 motor. 
Seems the Grasshopper uses 9T pinion and Hornet (same gearbox but 540 motor) uses 18t pinion.
So you will need a pinion with 9 teeth less than the factory 540 motor uses when installing the 380 motor and mount.
On Grasshopper the pinion comes pre fitted so you will need another pinion if the M06 uses anything other than 18 pinion when using the 540 motor..
Edit: I see one of the M06 options are 18t pinion, so you can use the Grasshopper 380 motor and pinion as long at the Grasshopper mount will fit.