Maybe you meant that as a search instead of a support question?

https://www.google.com/search?q=gmail+text+message&ie=utf-8&oe=utf-8&client=firefox-b-1

How do I add SMS to my Gmail account? Here's how to use it:

   Log into your Google account.
   Click on the Labs icon in the top-right corner of the page (it looks like a laboratory flask).
   Scroll down to the Text Messaging (SMS) in Chat option and click Enable.
   Return to your main Gmail page and put your cursor on a contact from your Chat list.

Can't find the Labs in the upper right

Hi oliviag126, if you don't find the feature, you could ask about it on Google's support forum for Gmail:

https://productforums.google.com/forum/#!forum/gmail

OK thanks