php-flasher/docs/assets/js/controllers/theme_onyx_controller.js

import { Controller } from '@hotwired/stimulus'
import { showNotificationsForHandler } from '../show_notifications'

import '@flasher/flasher/dist/themes/onyx/onyx.min.css'

export default class extends Controller {
    connect() {
        showNotificationsForHandler('theme.onyx')
    }
}