your script tag should look like this:
<script src="./node_modules/bootstrap-input-spinner/src/bootstrap-input-spinner.js"></script>
your script tag should look like this:
<script src="./node_modules/bootstrap-input-spinner/src/bootstrap-input-spinner.js"></script>
My HTML body code:
<body>
<div class="container">
<h1> Calculator</h1>
<div class="card">
<div class="card-body">
<input type="number" value="0" min="0" max="100" step="1"/>
</div>
</div>
</div>
<script src="/node_modules/bootstrap-input-spinner.js"></script>
<script>
$("input[type='number']").inputSpinner();
</script>
</body>
I also include bootstrap cdn in my project