If your bike is in warranty and you have motor problems, I think the LBS will just send it back to the manufacturer for service. I don't think they have the proper training and access to the parts. If your bike is out of warranty and need service or overhaul of the motor, look for an ebike motor repair specialist. These guys specialize in ebike motor work and have worldwide partners. My buddy used them to repair his Brose motor and they did a great job:
eBike Motor Parts Repairs & Servicing, (formally, Performance Line Bearings) has become the “go to place” for all your e-Bike motor repairs...
www.ebikemotorcentre.com