how can i alter the index js in the fact skill template to accept ssml tags? /

I'm using the Fact Skill template playing with breaks,pitches, volume etc... with Alexa's speech.
Index js Example: "Jupiter is really freaking big!"whether I try and add any ssml tag between the quotes( "Jupiter is really freaking big Alexa will just read the tag.whether I replace the quotes with tags the program doesn't run.
Where in the code effect I need to alter or add something to be able insert ssml tags between the quotes or change the code where speak tags are required?Thanks!

Source: amazon.com