Ember-paper and class?

I'm working on a project made with Ember.js I'm using ember-paper for buttons and also Ember-intl to translate my application (english and french). I have a basic HTML button with this code :

<button class= ></button>

But when I use ember-paper with this kind of code :

Test

I can't find a way to add my if statement and the action.

 >

Do you know how to do that ?

Thanks for your help !