Add text to Home page for Dev and Test environments

Summary

Add text to Home page for Dev and Test environments

Content

Hi,

We are wanting to add some text to the home page of our Dev and Test environments but are unsure how to do this. 

I have gone into a Sandbox and then selected Edit Page > Select and tried to add a Text and a Box component but just get the following error  "There are no boxes on the page, so you cannot add any content. Make sure your page (or the template it was based upon) includes at least one box before attempting to add content."

Please can someone advise how we can achieve this.