Change the last line there to
Add Force at Position is a member of Rigidbody not GameObject https://docs.unity3d.com/ScriptReference/Rigidbody.AddForceAtPosition.html
theRB.AddForceAtPosition(nutSpeed);Add Force at Position is a member of Rigidbody not GameObject https://docs.unity3d.com/ScriptReference/Rigidbody.AddForceAtPosition.html