You can bypass the control panel to confirm whether the problem is in the panel (quite likely) or somewhere else. Follow the cable all the way to the motor controller to find the connector. Typically, there are 4 wires in the cable to the meter. Colours are normally red, black, blue and green, but there are some variations on that, especially if you have the light switch in the control panel. Disconnect the control panel and make a bridge between the red and the blue wires. That will make the pedal assist work on the lowest power level, and if you have a throttle, it'll work normally.
If you have different wires to what I describe, show us a clear photo, not some tangled mess.
MTF Enterprises announces acquisition of EMU Electric Bikes
Wisper 806T folding bike wins Which? ‘Best Buy’
Sustrans calls for protected cycle lanes
Amazon launch their first UK e-cargo micromobility hub