Javascript to trigger submit when enter is pressed

I Have a password form and I want the enter key to trigger the submit button but I can't seem to get it to work. I know they can view source to see password this is just for practice example.

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<form>
        <input id="user" type="text" name="username" 
placeholder="username">
        <input id="pass" type="password" id="pass" name="password">
        <input id="subm"type="button" name="submit" value="submit" 
onclick="checkPswd();">
</form>    
</body>

<script type="text/javascript">  
       function checkPswd(){
        var confirmpassword = "admin";
        var username = document.getElementById('user').value;
        var password = document.getElementById("pass").value;

            if(password == confirmpassword){

                window.location.href = "redu.html";

            }else{
                alert('try again');
            }

       };

 </script>    
</html>

Solution

you need to add id, action, submit type, prevent default and listener. checkout my snippet..

have a nice day!

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    
    <!-- add id and action -->
    <form id="example" action="#">
        <input id="user" type="text" name="username" placeholder="username">
        <input id="pass" type="password" id="pass" name="password">

        <!-- change type to submit -->
        <input id="subm" type="submit" name="submit" value="submit">
    </form>    
</body>

<script type="text/javascript"> 

//add listener
document.getElementById("example").addEventListener("submit", checkPswd, true);

function checkPswd(){
    var confirmpassword = "admin";
    var username = document.getElementById('user').value;
    var password = document.getElementById("pass").value;

    if(password == confirmpassword){

        window.location.href = "redu.html";

    }else{
        alert('try again');
    }

    //add prevent default
    event.preventDefault();
};

</script>    
</html>