How to use script tag in an ASP.NET Core MVC razor view

Question

I want to use javascript in a razor view in the MVC project. I want to show a message to the user by clicking the post button. I put the script tag in Section below the page but on hitting F12 it shows 'btn' is null . I'm testing my project on IISExpress in Firefox

<form method="post">
--------a few input fields in a form-------
 <button id="button" type="submit" class="btn btn-lg btn-success">send</button>
</form>
<div class="submit-progress d-none">
    <label>be patient please...</label>
</div>
@section scripts{
    <partial name="_ValidationScriptsPartial" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-fileinput/5.2.7/js/fileinput.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function () {
            const btn = document.getElementById("#button");
            btn.addEventListener("click", function () {
                $(btn).prop("disabled", true);
                $(".submit-progress").removeClass("d-none");
            })
        });
    </script>
}

Answer 1

When using getElementById you only need to pass the name not the selector #

const btn = document.getElementById("button");

You have used the scripts section correctly.

Answer 2

There are multiple problems with your code mostly from mixing jQuery and native JavaScript methods. You can make it work by fixing the 3 lines shown to use jQuery. Note that "this" refers to the element to which the event handler is attached, in this case the button.

$(document).ready(function() {
  // const btn = document.getElementById("#button"); <-- REMOVE
  $("#button").click(function() { // <-- CHANGE
    $(this).prop("disabled", true); // <-- CHANGE
    $(".submit-progress").removeClass("d-none");
  })
});