NullReferenceException at VehicleCache.getFuelError

please fix it

Failed to run a 3.00 timer in 'FuelAlarm v1.0.3' (NullReferenceException: Object reference not set to an instance of an object)
at Oxide.Plugins.FuelAlarm+VehicleCache.getFuel () [0x0000b] in <18bf3b3c43094a61bdaab261dc048cea>:0
at Oxide.Plugins.FuelAlarm.<AlarmManager>m__0 () [0x000a8] in <18bf3b3c43094a61bdaab261dc048cea>:0
at Oxide.Core.Libraries.Timer+TimerInstance.FireCallback () [0x00018] in <ec05e0208c9149bba43236ca58fea105>:0

Replace line 33 with:

return (entity?.GetParentEntity() as MotorRowboat)?.GetFuelSystem()?.GetFuelAmount() ?? 0;
okay, now no failure, but the alarm is always on

Screenshot: https://prnt.sc/yjb6jk

Text:

Failed to run a 3.00 timer in 'FuelAlarm v1.0.3' (NullReferenceException: Object reference not set to an instance of an object)
at Oxide.Plugins.FuelAlarm+VehicleCache.getFuel () [0x0000b] in <d867b5d0052a4988b55ee02399711dee>:0
at Oxide.Plugins.FuelAlarm.<AlarmManager>m__0 () [0x0004d] in <d867b5d0052a4988b55ee02399711dee>:0
at Oxide.Core.Libraries.Timer+TimerInstance.FireCallback () [0x00018] in <ec05e0208c9149bba43236ca58fea105>:0

i have the same error

I replaced the line and i can still hear the alarm