ng2-char: How to show the percentage inside the graph?

Question

I’m using ng2-Chart to generate the graphics. The problem I wanted to put the percentage or even the values inside the graph, but I couldn’t do that. In [options] step a plugin I saw the people on the Internet talking to do but still does not work:

  optionsGraficoDespesa: ChartOptions = {
    responsive: true,
    tooltips: {
      enabled: true,
      callbacks: {
        label: function (tooltipItem, data) {
          let label = data.labels[tooltipItem.index];
          let count: any = data
            .datasets[tooltipItem.datasetIndex]
            .data[tooltipItem.index];
          return label + ": " + new Intl.NumberFormat('pt-BR', { style: 'currency', currency: 'BRL' }).format(count);
        },
      },
    },
    plugins: {
      datalabels: {
        formatter: (value, ctx) => {
          let sum = 0;
          let dataArr = ctx.chart.data.datasets[0].data;
          dataArr.map(data => {
            sum += data;
          });
          let percentage = (value * 100 / sum).toFixed(2) + "%";
          return percentage;
        },
        color: '#fff',
      }
    }
  };

<canvas baseChart [data]="dashboard.graficoDespesaMensal.valorTotalDespesa"
                [labels]="dashboard.graficoDespesaMensal.descricaoCategoria" [options]="optionsGraficoDespesa"
                [chartType]="'doughnut'">
              </canvas>

Like this:

What I wanted was for you to show the percentage within each circle. Someone has already done that?