Change hit boxes (MC)?

I wanted to know if it was possible to change mobs' hit boxes (in Minecraft). So that they only take Schadem when I hit the head etc. How does that work? If you know a tutorial, bring it with you

Yes, it is, I'm just not quite sure how…

You can, I think only via plugins, query where, for example, a projectile is when it hits an entity. So you could only track headshots with a bow. But with a sword that is more difficult. Because you can't track where you hit.