It keeps moving after you release the controls

Follow the shutdown and isolation instructions for your model. This draft doesn’t supply a universal procedure.

Tell the repair person what continued moving and which control you had released. That detail explains the problem without another test. Don’t restart it to make a recording.

Describe where the snowblower is without trying to move unsafe equipment. This is one of those times when a house call can solve a very practical problem: you don’t have to transport a machine you’ve already stopped using. Ask whether they can assess it at that location and make the control problem clear before arranging anything.

Sending a message doesn’t make the machine safe to use, and you still need the repair business to confirm that they’ve accepted the visit.