It's literally a button, with some extra stuff attached to it. The only requirement for a button is that if it's accessible to the person trying to press it (no pictures posted of that, feel free to assume). But, there's intentional inaccessibility built into this project, so that may be an intentional goal.
Thats's the great part about home assistant though...anything that can change states, with intent/meaning, is waiting to be tied to an automation.