Cómo hacer un rectángulo en JavaScript
const canvas = document.getElementById('pong') // first make a index . html with a canvas height and width and id of pong or whatever
// and then we have to get access to our context to draw on it
const context = canvas.getContext('2d')
// then you do...
context.drawRect(20, 20, 150, 150);
context.fillStyle = '#fff' // thats white!!
Impossible Ibis