P5js get Battery Level

// Get Battery Level
// Read the current battery level with P5*js

var bl;

function setup() {
  frameRate(2);
  createCanvas(400, 400);
  fill(0);
  textAlign(CENTER);

  navigator.getBattery().then(function (battery) {
    bl = battery.level;
  });
}

function draw() {
  background(255);
  textSize(24);
  text("Your current battery level is", width / 2 , height / 2 - 35);
  textSize(64);
  text(bl * 100 + " %", width / 2, height / 2 + 35);
}