Alpine has full support for web components so we can use the <file-pond> custom element with Alpine as if it was any other HTML element. 

<script defer src="https://cdn.jsdelivr.net/npm/alpinejs@3.x.x/dist/cdn.min.js"></script>

<form x-data @submit.prevent="console.log($refs.pondRef.entries)" method="POST">
    <file-pond x-ref="pondRef" @change="console.log($el.entries)">
        <label for="my-file">Drop files here, or <u>browse</u></label>
        <input id="my-file" type="file" name="files" required multiple />
    </file-pond>

    <button type="submit">Sumbit</button>
</form>

<script type="module">
    // filepond imports
    import { defineFilePond } from 'filepond';
    import { locale } from 'filepond/locales/en-gb.js';

    // defines <file-pond> element
    defineFilePond({
        locale,
    });
</script>