[Vuejs]-Components as slot content Vue3

Have a look at the docs for named slots: https://vuejs.org/guide/components/slots.html

You can only use your parent code with the default slot, so your PkDynModalCenter should look like this:

<div class="...">
    <div id="modalIndicator" class="...">
        <slot></slot> <!-- no name → default slot -->
    </div>
</div>

With your current code for the modal, you can only call it like you did in your first code snippet.