---

<form id="myForm" action="send-contact.php" method="POST">
<input type="text" name="name" class="form-control" aria-label="Default" aria-describedby="inputGroup-sizing-default" placeholder="Ваше имя">
<input type="text" name="phone" class="form-control mask-phone" aria-label="Default" aria-describedby="inputGroup-sizing-default" placeholder="Контактный телефон" required>
<button type="submit" id="myButton" class="btn btn-outline-success">Получить</button>
</form>

<script>
    $(document).ready(function () {

        $("#myForm").submit(function (e) {
            
           // Disable button for submitting
            $("#myButton").attr("disabled", true);

            return true;

        });
    });
</script>