If we use the quote collectTotal() method in our custom requirement then it’s possible that total won’t get loaded in the cart summary and checkout summary.

So how to reload summary total by using JS.

You have to use Magento_Checkout/js/action/get-totals to update the summary.

define([
    'uiComponent',
    'jquery',
    'Magento_Checkout/js/action/get-totals',
    'ko',

], function (Component, $, getTotalsAction, ko) {
    'use strict';
    return Component.extend({
            var newUrl = baseUrl+'/loadSummary';
            $.ajax({
                url: newUrl,

                data:  {
                },
                type: "post",
                cache: false,
                success: function (data) {
                    var deferred = $.Deferred();
                    getTotalsAction([], deferred);
                }
            });
        
    });
});