Robots Text Editor
Robots.txt is a file that lives on the webserver, unseen by your users. Search engines use it to help determine how to index your site, and you can use it to help search engines along.
Editing this file is not necessary, but it can be beneficial in certain cases.
You must be a SuperAdmin or an Admin with the Content role to access this feature.
From the Admin panel, select Site Manager -> Robots Text Editor.
Make Edits to the File and Save
It's a simple text file, and you can find the required syntax and formatting for the file at http://www.robotstxt.org/
There's a useful, easy-to-use online tool for testing the effectiveness of your robots.txt file at https://technicalseo.com/tools/robots-txt/ .
NOTE: Aldrich Web Solutions has no affiliation with this TechnicalSEO tool.