Blueprint interface doesnt add Blueprint interface option in the left menu

It happens correctly in this video and in many others: How to use Blueprint interfaces in UE4, in 90s - Super-quick tutorial for beginners - YouTube
In my case is different, after i add the interface to an actor, compile it (compile everything), it doesnt appear the option in the left menu. I can create the event but there is no option to modify the interface function that i know of, please help.

In the interface itself you need to have an output. Otherwise it will be implemented as an event