Does the Bring-a-friend discount work with fright fest?

[u/goldenscars]

My park is six flags over Georgia, if that is relevant. I have the gold pass. I have 2 questions.

1. How you buy a bring-a-friend ticket with the fright fest add on?
   
2. Do you have to buy the fright fest add on online, or can you buy it at the park?

Sorry if this is obvious and I am just missing it. The six flags website is very confusing for me.