Charts.js callbacks doesn’t change regardless of the code

When hovering over a section I want to see the category its in as the title (A, B, C..) and some other data as the label. No matter what code I put in options.tooltip.callbacks nothing changes. The bellow bit is from the official docs here. I don’t understand what I’m doing wrong. Advice is very appreciated.

JS:

    var ctx = document.getElementById('greenhouse').getContext('2d');
    var myChart = new Chart(ctx, {
      type: 'bar',
      data: {
        labels: ['01', '02', '03', '04', '05', '06', '07', '08', '09', '10'],
        datasets: [{
            label: "A",
            data: [20, 20, 20, 20, 20, 20, 20, 20, 20, 20],
            backgroundColor: 'rgba(56, 158, 13, 1)',
          },
          {
            label: "B",
            data: [20, 20, 20, 20, 20, 20, 20, 20, 20, 20],
            backgroundColor: 'rgba(169, 201, 17, 1)',
          },
          {
            label: "C",
            data: [20, 20, 20, 20, 20, 20, 20, 20, 20, 20],
            backgroundColor: 'rgba(249, 157, 2, 1)',
          },
          {
            label: "D",
            data: [20, 20, 20, 20, 20, 20, 20, 20, 20, 20],
            backgroundColor: 'rgba(247, 89, 171, 1)',
          },
          {
            label: "E",
            data: [20, 20, 20, 20, 20, 20, 20, 20, 20, 20],
            backgroundColor: 'rgba(210, 97, 81, 1)',
          },
        ]
      },
      options: {
        plugins: {
          title: {
            display: true,
            text: 'Greenhouse'
          },
          tooltip: {
            callbacks: {
              label: function(data) {
                let label = data.dataset.label || '';

                if (label) {
                  label += ': ';
                }
                if (data.parsed.y !== null) {
                  label += new Intl.NumberFormat('en-US', {
                    style: 'currency',
                    currency: 'USD'
                  }).format(data.parsed.y);
                }
                return label;
              }
            }
          },

        },
        responsive: true,
        scales: {
          xAxes: [{
            stacked: true,
          }],
          yAxes: [{
            stacked: true,
          }],
        },
      },
    });

HTML:

    <link href="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.8.0/Chart.min.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.8.0/Chart.min.js"></script>
    <div class="container">
      <div class="row">
        <div class="col">
          <canvas id="greenhouse" width="100%"></canvas>
        </div>
      </div>
    </div>

jsfiddle – https://jsfiddle.net/o5jp7aqk/