Many of the sensors in the intergation contains additional attributes that gives more details. You can see these attributes if you click on the sensor in the user interface and expand the attributes at the bottom of the popup.

To access the attributes in an automation or similar you can use a template, like this:

{{ state_attr('sensor.j21_status', 'config_phaseMode') }}

Note that HA removes underscores (_) when it displays the name in the UI, so that has to be added back to be able to access it.