Errors on Roll a ball tutorial

Completely new to Unity Forum, Unity, and have only been coding for a few months. In C++. Anyway, after following the steps through the Roll-a-ball tutorial’s second video, MovingthePlayer I have an error saying

“Assets/Scripts/PlayerController.cs(16,27): error CS1061: Type UnityEngine.Rigidbody' does not contain a definition for Addforce’ and no extension method Addforce' of type UnityEngine.Rigidbody’ could be found (are you missing a using directive or an assembly reference?)”

This is my code. Any tips? Would using the free version of Unity be the problem? I don’t really have any idea what I’m doing so, maybe just telling me where to fix my code or just being specific would be great. Thanks.

You need AddForce not Addforce, case makes a difference, so the lowercase f is the issue.