Following the documentation here
Coding Device Interactions | Unreal Editor For Fortnite Documentation | Epic Developer Community (epicgames.com)
There are a couple errors in the code examples and instructions. Firstly
Binding Functions to Creative Device Events
The constant on line 13 should be Subscription and not ButtonSubscription which is already created and assigned on line 10. It should be Subscription because on line 16 we see that we are passing in that Subscription as an option to the setter.
In the next section of the documentation;
Spawning Item When Player Presses Button Example
Bullet 3 "Create a Verse device with editable properties for the Button device and Item Spawner device. See Adding a Verse Reference to a Creative Device in Your Level. "
Has a broken link. This just takes you to the base Unreal Editor For Fortnite Documentation | Unreal Editor For Fortnite Documentation | Epic Developer Community (epicgames.com) documentation.
Also in this section, if the learner is following along, and tries to start the game and press the button, nothing will happen. This is because nowhere in the instructions does it say to put your newly created verse device onto the actual level. (This may be discussed on the link that is broken, but as I can’t access this there is no way for me to tell if that is the case.)
And in the final Section;
Awaiting a Creative Device Event
Personally, I feel this section is too advanced without any instructions. It just shows a script but doesn’t tell the learner what trigger device to place or what buttons. It also says red or blue button, making a first-time learner think there are more than one button to choose from. For me I just went into custom meshes and made one red and one green. Again, not a huge thing or bug, more of a feedback callout.