Oracle Fusion Cloud Extensions with Visual Builder, how to test a new extension in unpublish sandbox

Summary:

Creating Oracle Fusion Cloud Extensions with Visual Builder, how to be tested in sandbox before published.

Content (required):

hello, I create an extension in Visual Builder, in a project, with workspace associated to an existing sandbox in Fusion Cloud Erp, I would like to see if works in the Fusion Cloud Erp, but If a choose publish button in Visual Builder it says that I have to refresh and publish the sandbox first, but I like to see if works fine in the sandbox first before publish the sandbox, please let me know how can I have the extension in the sandbox after publish it