With the Energy Planner you can indicate whether you want the battery to discharge towards the home or also towards the grid, during the time blocks you specify. Follow these steps to set it up:
Step 2: Configure Energy Planner
Go to Configuration and then to Energy Management. Click on 'Configure' in the 'Energy Planner' box.

Step 3: New Operating Mode
If you choose a 'new Operating Mode' here, there is an option for 'Feed-in'. Select this and click on 'Continue'

Step 4: Only PV or PV and battery?
The following question appears: Which part of the energy should be fed back to the public grid? You can choose 'Only PV Energy' or 'All'. With the latter it states: Feed back both the PV energy and the energy stored in your battery to the public grid. In other words: this is the option you must choose to be able to feed back from the battery to the grid.

Step 5: Power
You can also indicate here with which power the battery should be discharged: either the maximum possible or a lower, self-chosen value.

Step 6: Done
You can change the setting at any time, via the same steps.