filter for non-null fee type

compendium-frontend/src/pages/Organization/ChargingStructure.tsx

@@ -10,8 +10,11 @@ import { useData } from "../../helpers/useData";
 import PillTable from "../../components/PillTable";
 
 function ChargingStructurePage(): React.ReactElement {
+
+    const validityCheck = (data: ChargingStructure) => data.fee_type != null;
+
     const { filterSelection, setFilterSelection } = useContext(FilterSelectionContext);
-    const { data, years, nrens } = useData<ChargingStructure>('/api/charging/', setFilterSelection);
+    const { data, years, nrens } = useData<ChargingStructure>('/api/charging/', setFilterSelection, validityCheck);
 
     const selectedData = data.filter(data =>
         filterSelection.selectedYears.includes(data.year) && filterSelection.selectedNrens.includes(data.nren)