Where can I find the Unique name instance of Microsoft Dynamics 365?
Choose which Microsoft Dynamics 365 organization you want to connect to CRM Rapid App, you can choose between a production instance or a non-production instance (so called sandbox).
In Microsoft Dynamics 365, in the appropriate instance that you selected for the location of the CRM Rapid App, expand the menu Sales, select Settings and Customization.
In the menu that appears, select Developer Resources.
Here you can find the Unique name of your Microsoft Dynamics 365 instance.