You can create, access, and modify your sandboxes via the Manage Sandboxes page.
Create a sandbox
Create a sandbox by clicking on + Add a Sandbox company. You will be presented with a choice of selecting from the two QuickBooks SKUs – QuickBooks Online Plus or QuickBooks Online Advanced.
Delete sandbox data
You cannot delete sandboxes themselves, but you can delete the data contained within them.
From the Manage Sandboxes page, click Delete all data.
The following confirmation message displays:
Click Yes to proceed with the delete operation.
This action deletes all data objects for the target company, both originally supplied when the sandbox was first created and objects subsequently created via the UI or the QuickBooks Online API.