Creating a full data set copy of your instance - Dynamics 365

Usually Microsoft asks the customers to do a copy of their instance to debug an issue. 

you need to follow the below mentioned steps.

Reference for full data copy : https://docs.microsoft.com/en-us/dynamics365/customer-engagement/admin/copy-instance

Follow below steps for Copy of Instance:

1.       Browse to the Office 365 admin center and sign in using Office 365 Global administrator credentials.

2.       Click Admin centers > Dynamics 365.

3.       Choose the Instances tab.

4.       Select an instance, and then click Copy

Note: The org will be in “Administration Mode,” So please select the Support Instance click on Admin button and uncheck the Administration Mode check box