Simple thorns potion effect not working

Trying to make a thorns-like potion effect, but whenever I try to add the procedure to any of the custom potion effect's triggers, it says that dependencies are missing and won't allow me to add it as a trigger.

My code is:

Entity trigger: Entity attacked

If: [Has [event/target entity] active potion: CrystalSpikes]

do: [Deal 2 damage to [Source entity] type: MAGIC]

      [Play at X Y Z Leve 1 Pitch 1 sound : hurt_sweet_berry_bush]