How to make entity not attack a player with specific item in hand?

I tried to do something like the opposite of this, but it didn't seem to work: https://mcreator.net/forum/80483/tutorial-mobs-only-attack-player-if-wearing-or-holding-hand-particular-item?page=0

I'm trying to make a ranged item which summons a custom entity once the projectile lands, and that entity should attack everything except for the player who shot the projectile. When the projectile lands, the entity just stands there and walks around like a regular animal.

Any help is appreciated :)