Input range variable is not defined & can’t be collected

I have this form:

        <form name="myLoginForm" method="post">
            <div class="container">
                <label for="uname"><strong>Username</strong></label>
                <input id="uname" type="text" placeholder="Enter Username" name="uname" required>

                <label for="difficulty"><strong>Difficulty:</strong><br></label>
                <input type="range" id="difficulty" name="difficulty" min="0" max="10">

                <button id="startGame" type="button">Start Game</button>
            </div>
        </form>

I can’t grab the input value of my input range. This is what I’m trying right now:

            var selectedDifficulty = document.getElementById("difficulty").value
            var sd = parseInt(selectedDifficulty);