Display the changed value using “if” that was written in the textbox

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <input type="text" id="Username" />
    <input type="button" id="tutorial" value="Click" onclick="repeatvalue()" />
    <hr />
    <label id="label"></label>
    <script>
        function repeatvalue() {
            var txtName = document.getElementById("Username");
            var lblName = document.getElementById("label");


            if (label = "BE20R") {
                result = '5layer';
            } else {
                result = '3layer';
            }
            lblName.innerHTML = result;
        }
    </script>
</body>

</html>

This is just my first steps in JS, so I want to ask for help. What I want is that depending on what value I put in the textbox, JS will show the converted value. For example, if I enter “BE20R” I want it to show me “5layers”, if I enter another value – “3layers”.