Hi Titi- We accomplish this by creating a new free Eventbrite account and creating test events there. You will need an email address that is not already connected to an in-use Eventbrite, and use it at
eventbrite.com to create a new account. Setting up a new account is quick and easy. This has worked with sandbox testing for our Salesforce integration app, Eventbrite Fusion, and I think it should work with the free Eventbrite managed package too.