The system uses the “event point damage” by default:

You can locate this section in the “Monster Graph” inside “Monster_NPC”:

That means that you need to damage the monster with “ApplyPointDamage” node in Blueprint, this is an example i made in the unreal first person shooter example:

but also if you’d like to use the “ApplyDamage” you just need to disconnect the Event point damage and connect the apply damage:

you can call the apply damage from the gun, sword, or projectile when it touches the monster.
Note: when you apply damage you need to assign the damage causer, this is important cause the system use it when investigating the player like when hearing noise detected.
