How to use the @pnp/spfx-property-controls/lib/PropertyFieldMultiSelect.PropertyFieldMultiSelect function in @pnp/spfx-property-controls

return {
      pages: [
        {
          header: {
            description: strings.PropertyPaneDescription
          },
          groups: [
            {
              groupName: strings.ChartData,
              groupFields: [
                PropertyPaneDropdown('listId', {
                  label: strings.List,
                  options: this.listOptions,
                  disabled: this.listOptionsLoading,
                }),
                PropertyFieldMultiSelect('selectedFields', {
                  key: 'selectedFields',
                  label: strings.SelectedFields,
                  options: this.fieldOptions,
                  disabled: this.fieldOptionsLoading,
                  selectedKeys: this.properties.selectedFields,
                })
              ]
            },
            {
              groupName: strings.ChartSettings,
              groupFields: [
                PropertyPaneDropdown('chartType', {
                  label: strings.ChartType,
                  options: [
                    { key: 'Bar', text: strings.ChartBar },
                    { key: 'HorizontalBar', text: strings.ChartBarHorizontal },