I'm down to the wire in Price's tutorial. Come to find out there's no shadow feature in 4.3. Even the info online for 4.3 says where the check box is supposed to be but it isn't there. Is "shadow catcher" the same thing? I'm pretty sure it isn't. So please tell me, where the heck is it? I've searched online and got nothing!???
It would help if we knew what video you are talking about. 4.3 introduces eevee next. I'm assuming you are looking for eevee's shadow settings which are now in properties editor->World tab->Settings Panel->Shadow subpanel. If this isn't what you're looking for then let us know.