click submit button every 4 secconds

how can i make automatic click per each 4 sec ?

i want that submit button be clicked every 4 sec.
but its not work correctly

my works :

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>*BruteForce*</title>
    <script src="!Needs/jquery.min.js"></script>
    <style>
        #form {
            margin: 0 auto;
            text-align: center;
        }

        #getHash {
            width: 440px;
            text-align: center;
        }

        #length {
            text-align: center;
        }

        #boxContent {
            width: 833px;
            height: 469px;
            border: 1pt solid black;
            text-align: left;
            margin: 0 auto;
        }
    </style>
</head>
<body>
<form id="form" method="post" action="server.php">
    <span>Enter Your Hash (SHA256) : </span>
    <input id="getHash" type="text" value="" name="getHash" title="">
    <input id="length" type="number" value="" name="length" placeholder="Enter the Length">
    <input id="create" type="submit" value="create" title=""><br><br>

    <div id="boxContent"></div>
    <input id="btn" type="button" value="..." title=""><br><br>
</form>
<script>

    setInterval(function () {
        $("#create").click(function () {
            event.preventDefault();
            $("#boxContent").html(("Loading ..."));
            $.ajax({
                type: 'POST',
                url: "server.php",
                data: $("#form").serialize(),
                success: function (response) {
                    $("#boxContent").html((response));
                }
            });
        });
    }, 4000);


</script>
</body>
</html>

here is php :

<?php
$getHash = $_POST['getHash'];
$length = $_POST['length'];

function randGenerator()
{
    $length = "10";
    $characters = "0123456789abcdefghijklmnopqrstuvwxyz!@#";
    $charactersLength = strlen($characters);
    $randomString = '';
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $characters[rand(0, $charactersLength - 1)];
    }
    return $randomString;

}

function crack()
{
    global $getHash, $length;
    for ($i = 1; $i <= $length; $i++) {
        $text = randGenerator();
        $beHash = hash('sha256', $text);
        if ($beHash == $getHash) {
            echo "<span class='true'>" . $text . "</span>";
            echo "<br>";

        } else {
            echo "<span class='false'>" . $text . "</span>";
            echo "<br>";

        }
    }
}

crack();

as you can see . im trying to make simple brutforce method
but its manual , i want to create a auto .
i used setinterval for every 4 sec . but it doesnt work . ? any idea?