Hello, I am building my first amp email and I know that fallback is possible. The issue for me is how do I go about implementing the fallback - I know amp uses fallback tags but I also remember reading that the HTML email is also included so for example in my editor I would have:

AMP EMAIL CODE
HTML EMAIL CODE

Is that how it works? or do I have to also include the HTML email INSIDE the amp email? Does anyone have a boilerplate I can look at?