Unable to create flows off of sms keyword responses. "Message Body" field seems to be missing?

Hello! 

I’ve been following this help article: https://help.klaviyo.com/hc/en-us/articles/360049930372#signupdownvote as I want to be able to send personalized SMS’s based off of what our customers reply back to our SMS’s with. 

Aka, when we send an SMS asking our customers: “Do you want baking or cooking recipes?”

We want to reply back with a cookie recipe if they say baking and a chicken recipe if they say cooking. 

However, when I use the “SMS sent” metric trigger or conditional action I am unable to find the “Message Body” field that the instructions say to pull in order to respond to the keyword and track what our customers are saying. Any way to resolve this?