How to test protect_from_forgery with: :exception rails

I am using protect_from_forgery with: :exception in my application. It seems to work fine but I want to test it.

I have a form. I understand that every form has a authenticity token related with it while using protect_from_forgery, I want to create a situation when the authenticity token does not pass and throws an exception. I want to see how the browser will respond with the exception.

How would I be able to do that?