Mining entity on command

EDIT: I figured that out. If you're having the same problem, DM me on discord Marwinekk#0041 and I can tell you how to do that :)

Does anyone know how to possibly make an entity, that runs towards stone and breaks 3x3 blocks when i press - for example - shift? I searched in all the other older forums and there is no answer to that question, and I think a lot of people would benefit from knowing how to do that!