How To Add Labels to Bars and X-Axis in a Bar Graph in charts_flutter in Flutter?

I'm trying to add bar labels to the bars and X-axis label to the X-axis in a bar chart using charts_flutter. What am I missing?

My Code:

return [
      charts.Series<DashInvoiceModel, String>(
        id: 'DashInvoiceModel',
        domainFn: (DashInvoiceModel sales, _) => sales.month,
        measureFn: (DashInvoiceModel sales, _) => sales.sales,
        labelAccessorFn: (DashInvoiceModel sales, _) =>
            '${sales.month}: ${sales.sales}',
        data: bikeInvoicesData,
        fillColorFn: (DashInvoiceModel sales, _) {
          return charts.MaterialPalette.blue.shadeDefault;
        },
      ),
      charts.Series<DashInvoiceModel, String>(
        id: 'DashInvoiceModel',
        domainFn: (DashInvoiceModel sales, _) => sales.month,
        measureFn: (DashInvoiceModel sales, _) => sales.sales,
         labelAccessorFn: (DashInvoiceModel sales, _) =>
            '${sales.month}: ${sales.sales}',
        data: carInvoicesData,
        fillColorFn: (DashInvoiceModel sales, _) {
          return charts.MaterialPalette.red.shadeDefault;
        },
      ),
    ];
  }

  barChart() {
    return charts.BarChart(
      List.from(seriesList),
      barRendererDecorator: (charts.BarLabelDecorator<String>(
        insideLabelStyleSpec: TextStyleSpec(fontSize: 12, color: Color.black),
        labelPosition: BarLabelPosition.inside,
        labelAnchor: BarLabelAnchor.end,
      )),
      vertical: true,
      barGroupingType: charts.BarGroupingType.grouped,
      defaultRenderer: charts.BarRendererConfig(
        groupingType: charts.BarGroupingType.grouped,
        strokeWidthPx: 1.0,
      ),
      domainAxis: charts.OrdinalAxisSpec(
        renderSpec: charts.NoneRenderSpec(),
      ),
    );
  } 

Sample of what I want:

What I get:

Similar to Sample but missing X-axis labels (2014,2015,etc) and Bar Labels ($5,$25,etc). What I am getting are the Y-axis labels (0, 50, 100,etc). My chart is grouped with two bars per group.

Version & Dependencies:

version: 1.0.0+1 sdk: ">=2.12.0 <3.0.1" charts_flutter: ^0.12.0