Very basic question on Blueprint events

Thanks for your reply,
but in this level blueprint this specific event is used 11 times (4 pieces can be seen in the editor) and I am not able to add at least one more.

I worked with basic blueprints. For e.g. doors that can be opened …
Now I try to understand how blueprints are used in such projects. The Wave calls the function to spawn a definable amount of enemies (e.g. “SpawNormalMacro”). They are spwan from brewery object (in this case from enemy brewery). In my understanding it waits until the amount of enemies are spawned and this is followed by a Delay to spawn next type of enemies.