If the BMW LCD key locks the screen, you can first try to restart the LCD screen, press the unlock button and lock button on the key, or insert the key into the ignition hole in the car and start the vehicle to see if it can be restored to normal.
If these methods do not work, it may be that the LCD screen is malfunctioning and you need to contact a BMW authorized repair center for further inspection and repair. In the process of handling, be sure to follow the relevant instructions in the user manual of BMW vehicles to avoid causing more serious problems.