AJO - Test push in Campaigns

Yes there is, but it does require some configuration. Here’s the page to test using an Event: https://experienceleague.adobe.com/en/docs/journey-optimizer/using/channels/push/push-config/push-configuration#mobile-app-test

Else, a simple way to do it would be to build a small audience (maybe yourself and your QA team), create a journey/campaign and send your push notification. This is how I currently test my process without going through the process described in the link above. 

The Simulate Content for Push only provides a screenshot on how the message will appear via the device.