Push Notifications stuck in 'Queued'

Hi,

I’m having some issues getting my push notifications to come through in development. I’m trying to send push notifications to a web browser to test, but all of my push notifications are in a Queued status. Here’s an example response from the status route:

{"errors":[],"app_id":"60886d78","ios":{"failure_reason":"","success":false,"sent":0},"status":"Queued","android":{"failure_reason":"","success":false,"sent":0}}

Is this normal behavior in development? How can I test push notifications in a web browser?

Thanks