What if the LINKT device doesn't beep when driving through the gantry?
Every car on Drive mate must have a toll tag (LINKT device) on it. If you don't see a device or it doesn't beep, the charges will still be incurred. So the guests have nothing to worry.
If the guest finds this issue of the car not having a LINKT device/ not beeping while driving through the gantry, they should immediately report it to Drive mate. Remember the respective toll charges will still be applicable.
If it is your own LINKT device, then you will need to ensure that it is working else Drive mate will not be able to charge the guest. Since it is the host's device, they are responsible for ensuring that the device works.
If it is a device provided by Drive mate and it is not working, then Drive mate will provide you a replacement device free of charge. However, if the device has been lost, then a replacement fee of $30 shall be applicable.