Stuck throttle open on specialized turbo electric pedal-assist bike
There is no 'throttle' control on pedal assist e-bikes, just a setting for the amount of assistance, so there is nothing to 'get stuck'.

If the motor spins the wheel aand delivers max torque regardless of pedaling force or speed, there is an electronic control problem. Most likely a sensor is broken, or even just come loose.

The only thing you can do is take it to a Specialized dealer bike store. Only they will have the knowledge and tools to diagnose the issue and fix it.