C# Input Key Named: Alpha1 is Unknown

I’ve been trying to create a script using the number keys. For some reason I’m getting this error Input Key named: Alpha1 is unknown and it points to the following line of code below. But I don’t understand why. Any idea what’s wrong?

if(Input.GetKeyDown("Alpha1")){}

Use KeyCode enums, not strings. GetKeyDown(KeyCode.Alpha1)