https://github.com/transloadit/uppy/issues/1627

uppy_sweetalert2_bug_fix.html

<div id="uppy"></div>
<button id="show-uppy-btn">Show Uppy</button>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/uppy@1.0.2/dist/uppy.min.css">
<script src="https://cdn.jsdelivr.net/npm/uppy@1.0.2/dist/uppy.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/sweetalert2@8.11.7/dist/sweetalert2.all.min.js"></script>
<script>
document.addEventListener('DOMContentLoaded', () => {

	const uppy = Uppy.Core().use(Uppy.Dashboard, {
		target: '#uppy',
		trigger: '#show-uppy-btn'
	});

	Swal.fire({ toast: true });

});
</script>