JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraphcore.js"></script>
<link rel="stylesheet" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css">
<div id="jxgbox"></div>

CSS

#jxgbox {
    width: 500px;
    height: 500px;
}

JavaScript

JXG.Options.text.display = 'internal';
var board = JXG.JSXGraph.initBoard('jxgbox', {
    boundingbox: [-5, 5, 5, -5],
    axis: false,
    grid: true
});

var p1 = board.create('point', [-2, -1], {fixed: false});
var p2 = board.create('point', [1, -1]);
var p3 = board.create('point', [1, 1]);
var p4 = board.create('point', [2, 1]);
var polygon = board.createElement('polygon', [p1, p2, p3, p4], { 
					hasInnerPoints : true
				});