Once you have selected a charging location - and, if applicable, a connection - in the app, you will find the rates for MobilityPlus subscribers at the bottom of the screen.
In the list form of the charging stations near you, you will see not only the rates for MobilityPlus subscribers, but also the official rates.
Tap the 'List' icon on the map
In the screen that opens up next, you will find all the stations near your location.
Prices marked with an * are the rates for MobilityPlus subscribers: