After theInitial Configurationinitial configuration of the ContentStore the very next thing you should do is configure the instances in the }APQ UX Instance dimension.
Until the instances defined in the instances.json file are set up as elements in the }APQ UX Instance dimension default values for the settings service won't be able to be stored, nor will default settings and options json and view definitions for widgets.
However, ...
Note #1 if you run the metadata syncing service then the service will create the instances for you (along with the rest of the instance metadata).
Note #2 in the App Management if creating a widget where instance name and cube name are specified as sources for the view definition then the instance will be created automatically if it doeesn't already exist.
So strictly speaking this step isn't required.
However, ...
Reason #1 to do it, it's extremely quick and will only take a few seconds to do manually in Arc
Reason #2 to do it, completing this step will allow you to manually configure default elements for the settings service and default view layouts per cube even without having run the metadata syncing service.
In the }APQ UX Instance dimension create LEAF elements per instance rolling up to the "Total Instances" parent.
• As html is case sensitive the instance names defined as the element principal name must be exactly as defined in instances.json
You can also enter data in the }APQ UX Instance Attributes cube but this isn't required unless running the metadata syncing service.