How do I insert the text inside the canvas using the buttons onclick function?

As mentioned in the title I want to be able to insert the text from the textbox to inside the canvas using the buttons onclick function. Now have in mind I'm a newbie at this so there may be errors all over the place.

function startGame() {
    myGameArea.start();
}
    
var myGameArea = {
    canvas : document.createElement("canvas"),
    start : function() {
        this.canvas.width = 480;
        this.canvas.height = 270;
        this.context = this.canvas.getContext("2d");
        this.gravity = 0.05;
        this.gravitySpeed = 0;
        document.body.insertBefore(this.canvas, document.body.childNodes[0]);
            
        }
}
    
function myFunction() {
    
}

canvas { 
  border: 1px solid #d3d3d3;
  background-color: #f1f1f1;
}

<body onload="startGame()">
<input type="text" name="Box" id="Box" value="" placeholder="Write whatever"/>
<button onclick="myFunction()">Submit</button>
</body>

Solution

@sosa123, Check below solution and let me know is this solution works for you or not?

<!DOCTYPE html>
<html>
<head>
<title>Page Title</title>
<script>
function startGame() {
    myGameArea.start();
}

var myGameArea = {
    canvas : createElementOnDom('CANVAS','myCANVAS'),
    start : function() {
        this.canvas.width = 480;
        this.canvas.height = 270;
        this.context = this.canvas.getContext("2d");
        this.gravity = 0.05;
        this.gravitySpeed = 0;
        document.body.insertBefore(this.canvas,document.body.childNodes[0]);

        }
}

    function createElementOnDom (type,id) {
   var element=document.createElement(type);
   element.id=id;
   return element;
}
function myFunction() {
    var canvas = document.getElementById("myCANVAS");
var ctx = canvas.getContext("2d");
ctx.font = "30px Arial";
ctx.fillText(document.getElementById("Box").value,10,50);
}
</script>
<style>
canvas { 
  border: 1px solid #d3d3d3;
  background-color: #f1f1f1;
}
</style>
</head>
<body>
<body onload="startGame()">
<input type="text" name="Box" id="Box" value="" placeholder="Write whatever"/>
<button onclick="myFunction()">Submit</button>
</body>
</body>
</html>