app/javascript/active_admin/features/main_menu.js
import Rails from '@rails/ujs';
const toggleMenu = function(event) {
const parent = this.parentNode
if (!("open" in parent.dataset)) {
parent.dataset.open = ""
} else {
delete parent.dataset.open
}
}
Rails.delegate(document, "#main-menu [data-menu-button]", "click", toggleMenu)