Caould you provide clear examples, hot it can be used with vue?

For example, I need to process button handler, how I can do this:

Code:
<template>
    <ext-button
        text="BUTTON"
        handler="?????"
    />
</template>


<script>
import "@sencha/ext-web-components/lib/ext-button.component";


export default {
    "name": "Test",
    "methods": {
        "onButtonClick": () => { alert( 'clicked' ) },
    },
};
</script>