Find an existing "Content Snippet" called "Head/Bottom". Or create a new Content Snippet named "Head/Bottom" and set the "Type" field to "HTML". Then add the following line into the Value (HTML) textarea:
<meta name="robots" content="noindex, nofollow">
The Head/Bottom Content Snippet is used to add, as the name already suggests, any HTML code near the bottom of the <head /> element, inside the page's <html /> element.
