how the cube will stand on the floor in a parcur game

Can you help with the code?
I’m creating a parkour game and everything went well but I got stuck on it:
as the cube will stand on the floor.
Here is my js code:

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


      var width = canvas.width;
      var height = canvas.height;


      var gameOver = function () {
         clearInterval(intervalId);
         ctx.font = "60px Caurier";
         ctx.textAlign = "cener";
         ctx.textBaseline = "middle";
         ctxfillText("GAME OVER", width / 2, height / 2);
      };


      var cicle = function (x, y, radius, fillCircle) {
         ctx.beginPath();
         ctx.arc(x, y, radius, 0, Math.PI * 2, false);
         if (fillCircle) {
            ctx.fill();
         } else {
            ctx.stroke();
         }
      };


      //Людина
      //намалювати
      function Draw() {
         this.x = 10;
         this.y = 10;

      }
      Draw.prototype.draw = function () {
         ctx.beginPath();
         ctx.moveTo(this.x, this.y);
         ctx.lineTo(this.x + 50, this.y);
         ctx.lineTo(this.x + 50, this.y + 50);
         ctx.lineTo(this.x, this.y + 50);
         ctx.lineTo(this.x, this.y);
         ctx.fill();
      }
      Draw.prototype.move = function () {
         if (this.x < 0) {
            this.x = 0;
         } else if (this.x > 1250) {
            this.x = 1250;
         }
         if (this.y < 0) {
            this.y = 0;
         } else if (this.y > 450) {
            this.y = 450;
         }

         while (this.y < 450) {
            this.y++;
         }
      }
      Draw.prototype.setDirection = function (direction) {
         if (direction === "left") {
            this.x = this.x - 10;
         } else if (direction === "right") {
            this.x = this.x + 10;
         } else if (direction === "up") {
            this.y = this.y - 150;
         }
      }
      var person = new Draw;

      var keyActions = {
         37: "left",
         38: "up",
         39: "right"
      };
      $("body").keydown(function (event) {
         var direction = keyActions[event.keyCode];
         person.setDirection(direction);
      });

      setInterval(function () {
         ctx.clearRect(0, 0, 1300, 500);
         person.draw();
         person.move();
         //карта
         var floor = ctx.strokeStyle = "LimeGreen"; ctx.lineWidth = 4; ctx.strokeRect(0, 312, 1300, 362);
      }, 30);

I tried a lot but it didn’t work out.
For example, I tried this:
first the code checks whether the cube and the floor are in the same coordinates, if so it reflects, if not, then no.