Overlap event not firing?

I have a collision sphere on my player character that is set to only have collision on at the end of its attack (A bite). I gave the component an overlap event that leads to Apply Damage. On the test enemies I have placed I set them to destroy actor whenever they take any damage. When I test this I can clearly see the collision sphere take effect but seeing as I put a print string on apply damage no damage is taken and nothing else happens.
I take it I missed a step?

Show components, bp… if applydamage = 0 then this event is not fired.

I set apply damage to 4