Thruster not Idle or running

recently i try to test my thruster. But it not running or even idling. its only sound the set-up beep. I’m using pixhawk 2.4.8 and BLHeli ESC. I have connect the rail with UBEC and set the parameter to use main 1 pin, reset the firmware and param, even try to change the pixhawk but it don’t work. any idea what i should do?