The charger reads the net power of the household from the HomeWizard meter: consumption minus production. As soon as the surplus is large enough for the chosen solar strategy, the charger starts a session, provided a car is connected and the session is authorised.
That is the whole mechanism. The HomeWizard link only reads the meter data; it is not an energy management system that controls the charger. Rules such as "the car always has priority over the home battery" cannot be set in the charger or in the HomeWizard app.
If you want priority rules
Use an energy management system that controls both the battery and the charger based on your own rules. The charger can be controlled through its local API, but this is not plug and play and requires technical knowledge. See the developer information for the API. More about the solar strategies: How does solar charging work with Peblar?