Conditionally display button

In Aurena 10 I have a custom Commandgroups button (ExecuteAction), on the Change Request page, linked to an API.

How can make it so that this button will only show when certain conditions on a Change Request are met?

An example of this is the out of the box “Create CO” button that will only show when the EcoNo is null and the Objstate is Active (Not Cancelled or Preliminary). It uses this script in the Enabled configuration of the button.

{"and":[{"==":[{"var":"record.EcoNo"},null]},{"!=":[{"var":"record.Objstate"},"Cancelled"]},{"!=":[{"var":"record.Objstate"},"Preliminary"]}]}

When I grab this and enter it for my button under the Enabled configuration it does not work. The button always shows on the page all the time.

Thanks.