Plastic electrical boxes that hold 1 electrical receptacle have rectangular "knock-outs" in them, so the circular types of wire clamps used to clamp wires into metal boxes can't be used. Are the knock-outs also supposed to work as clamps? Or are there special clamps that work with plastic boxes?
One Youtube video I saw says to "staple the wire within 8 inches of the box", which i assume means to staple the wire to a stud. That wouldn't be hard to do in new construction, but stapled wires could make it hard on someone trying to rewire an existing situation.