You can backup and restore Dynamics 365 databases through the Dynamics 365 Admin Center.
To do this, go to the Admin Center and select Backup and Restore:
Choose the organization to back up and select New backup:
Enter a label and any notes and click Create:
You will see the backup listed with a Creating status:
Once complete the status will be Available. From here you will be able to Edit and Delete:
Note you can only restore sandbox instances, as defined by a setting in your environment:
