If you are trying to call the button from the Incident.Brief form as part of a preview then the button will not work as that panel is read only.
I would raise a support call if you would like to see a feature introduced where buttons could work in that space. You can still have the button/action you want on the quick action toolbar as part of the list view and run it against single or multiple records.
Thank you for this. I will see if I can get a support call to have this feature added.