Creating a Brochure in Adobe Spark - how to add art to the flipside

I'm currently creating a brochure in Adobe Spark and its a very user-friendly and flexible process. However, I realized that I'm not certain how to "flip" the brochure over and add artwork or additional text to the backside. 

Are there any tutorials available or an experienced user who knows how to accomplish this? 

Thank you! 

HankCreativeArt