<script src='path/to/shodo.js'></script>
<canvas id="canvas" width=500 height="600"></canvas>
<script type="text/javascript">
let canvas = new Shodo.Canvas('canvas');
let brush = new Shodo.Brush(canvas);
brush.width = 20;
brush.blur = 10;
brush.tipAngle = Math.PI/4.0;
</script>
or
const Shodo = require('shodojs');
let canvas = new Shodo.Canvas('canvas');
...