How to use Plone 5 spinner?

Plone Support Add-on Development
1

I'm following this pattern to show spinner in this pull request but it is not working.

Can someone help me on how to use Plone 5 default spinner?

2

My code is right, but spinner just work for authenticated users: https://github.com/plone/mockup/issues/745

The HTML element is there, but it looks like we miss some CSS to show the spinner

Thank you @yenzenz for your help at #plone

3

this code should be available for unauthenticated users.

Can someone guide me where to change?