Why doesn't onclick work in MVC view?

Question

I had a project months ago where I used onclick and it worked great. First I wrote the anchor:

<a type="button" class="btn btn-primary" onclick="showpartial(14, 25, 'Test Product')" data-hint="Quick View"            data-bs-toggle="modal" data-bs-target="#myBox">
    View
</a>

Then I added some Javascript:

<script>
    function showpartial(id, price, name) {
        document.getElementById("myid").innerHTML = id;
        document.getElementById("myprice").innerHTML = price;
        document.getElementById("myname").innerHTML = name;
    }
</script>

and finally I wrote a modal (I'll do just a couple lines):

<div class="modal fade" id="myBox">
    <div class="modal-dialog modal-lg">
        <div class="modal-content">
            ...
        </div>
    </div>
</div>

But when I copied this code to a new project, it won't work. I click on the button and nothing at all happens.

I'm sure I'm forgetting something I probably added in the original project that's not here.

I'm using Firefox, and there's no debug messages showing errors.

Windows 10

VS 2019

.Net 4.7.2

bootstrap 5.0.1

Any suggestions on what to look for?