Render the chart with the specified objects selectable. This allows you to make objects selectable, even if they are not because they have a non-free status (e.g. booked, or a custom status).
You can pass object labels inside the array, like this:
selectableObjects: ['A-1', 'A-2']
selectableObjects has no effect on objects that are not-for-sale, nor on objects that are blocked by social distancing rules.