How to add the Synchronised Data Extension to my DESelect Segment account?

If you are using Salesforce as a CRM and you want to work with the Synchronised Data Extensions in DESelect Segment, they should be available for you in DESelect Segment. 

You can check this by clicking on the funnel icon on the Available DEs and see if the Synchronised DEs folder is listed there.

 If these are not already available in your DESelect Segment account, please raise a Support ticket requesting this.