JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdn.flexmonster.com/flexmonster.js"></script>

<div id="pivot-container"></div>

CSS

#fm-fields-view {
  top: -70px !important;
  height: 360px;
}

#fm-pivot-view #fm-fields-view .fm-popup-content .fm-ui-col-3 {
  height: 200px !important;
}

JavaScript

var pivot = new Flexmonster({
  container: "pivot-container",
  componentFolder: "https://cdn.flexmonster.com/",
  toolbar: true,
  report: {
    dataSource: {
      data: getData(),
      mapping: {
        "Date": {
          type: "year/month/day"
        },
        "Value": {
          type: "number"
        },
        "Category": {
          type: "string"
        }
      }
    },
    slice: {
      rows: [{
        "uniqueName": "Date"
      }],
      columns: [{
        "uniqueName": "[Measures]",
        "uniqueName": "Category"
      }],
      measures: [{
        "uniqueName": "Value",
        "aggregation": "sum"
      }]
    },
    options: {
      grid: {
        showEmptyValues: true
      }
    }
  }
});

function getData() {
  return [{
      "Date": "2016-03-20",
      "Value": 20,
      "Category": "Red"
    },
    {
      "Date": "2017-04-09",
      "Value": 21,
			"Category": "Red"
    },
    {
      "Date": "2017-05-10",
    },
    {
      "Date": "2018-11-27"
    },
    {
      "Date": "2019-02-18"
    },
    {
      "Date": "2020-06-23",
      "Value": 26,
			"Category": "Blue"
    },
  ];
}