How to listen to add a callback to Sortable.onEnd for the x-sort plugin?

[boosh]

How can I add a callback handler to onEnd? I can't seem to get the Sortable instance:

    document.addEventListener('alpine:init', () => {
        // Always undefined
        if (typeof Sortable !== 'undefined') {
            document.querySelectorAll('[x-sort]').forEach(el => {
                const sortableInstance = Sortable.get(el);
                if (sortableInstance) {
                    sortableInstance.option('onEnd', handleSortEnd);
                }
            });
        }
    });

Sortable is undefined.

[boosh]

Nevermind, I just added a handler on dragend.