How to re enable sending sms using gmail

     I found out that new Gmail accounts do not have the option to enable SMS in Chat through the Labs tab in Settings.  But I have an email I set up awhile ago with this enabled and it's still appearing.   Does anyone know if this feature has been discontinued for new accounts? Or if there is a way to get it on new accounts? 
 I have answer also for that all question..... 

The feature is still available, but it's not compatible with new Hangouts.  Since all new accounts have new Hangouts enabled by default, the SMS lab doesn't appear, but you can get it if you switch the account back to old chat.  Click on your name at the top of the Hangouts pane, then select Revert to old chat.

Look at the video I have created...