Collider not working

Hello everyone! I did this tutorial on time trial system and it seem when colliding with the object nothing happens. And this error appears:

“NullReferenceException: Object reference not set to an instance of an object
GainTime.OnTriggerEnter (UnityEngine.Collider Col) (at Assets/Script/GainTime.js:14)”

I really need help ASAP guys thanks!

Screenshots:

You don’t have an object in your hierarchy called “Player” with a MoveSceneTimer component attached.