I am trying to setup my own smart devices, but of course I want the user to authorize before logging in to my application. I would rather not do it with OAuth, simply because Google Sign-in is way easier. However, this can only be enabled when you set the Do you want to allow users to sign up for new accounts via voice? option to yes. Unfotunately this option does not seem to be there in the actions console. 
What is the reason I can't select this? Are there extra requirements for it?