There are multiple ways to do this, but if you’re trying to get the enemy to react, you could do something similar to this function for making a projectile deal damage to an enemy/player by letting them know that they’ve been hit and telling them to run a function to hurt themselves essentially:
This particular function, ReceiveHit, is a collision detection event that is being overridden from a base class in the engine, but it can give you a good idea. This particular projectile is only suppose to deal damage to a certain class, therefore I have it store a cast to that particular class using the ‘Other’ (The other actor that is being hit) variable in a pointer. This will determine if the thing being hit is indeed that class. I then use an If statement to check and have the pointer call ReceiveDamage on that object so that it gets hurt.