How do you refer to a object in an constructor inside the same class in another function in javascript?

Question

How do you refer to a object in an constructor inside the same class in another function? I have tried console logging the different keystrokes, which seems to be working. The thing that is not working is adding and subtracting from this.x and this.y. And also it seems the drawChar(this.x,this.y) is not working as well. Here is the code:

var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");

var w = (canvas.width = window.innerWidth);
var h = (canvas.height = window.innerHeight);

function drawChar(x, y) {
  ctx.fillStyle = `black`;

  ctx.fillRect(x, y, 20, 20);
}

class Character {
  constructor() {
    this.x = w / 2;
    this.y = h / 2;
  }

  move(event) {
    let k = event.keyCode;

    if (k == 87) {
      this.y = this.y - 5;
    }

    if (k == 83) {
      this.y = this.y + 5;
    }

    if (k == 68) {
      this.x = this.x + 5;
    }

    if (k == 65) {
      this.x = this.x - 5;
    }

    drawChar(this.x, this.y);

  }
}

let player1;
player1 = new Character();

document.addEventListener("keydown", player1.move);