Snippet to get the next page using ajax in WordPress

wp-ajax-get.js

   /*!
    ♡♡♡♡♡♡♡♡♡♡♡
    ♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥
    Async functionality
    ♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥
    ♡♡♡♡♡♡♡♡♡♡♡
    */
    $(document).on('click', '#page a:not([target="_blank"]):not([href="#"]):not(.btn), [href^="/"]', function (e) {
        var $this = $(this),
            $page = $this.attr('href'),
            pathname = this.pathname;
        e.preventDefault();
        $('body').removeClass('page-loaded').addClass('page-loading');

        $.get({
            url: $page,
            cache: true
        }, function (data) {

            var $items = $(data).find('#page-wrapper'),
                title = $(data).filter('title').text();
            // console.log($items);
            // html = $(data).html;
            let parser = new DOMParser(),
                doc = parser.parseFromString(data, "text/html"),
                // body classes
                docTheme = doc.body.getAttribute('data-themeify'),
                docClass = doc.body.getAttribute('class');
            // Garbage collection, you don't need this anymore.
            parser = doc = null;
            // history.pushState({"html":html}, '', $page);
            history.pushState('', '', pathname);
            // windowHeight = $(window).height();

            closeMenu();

            //can wait til images are loaded, otherwise just render the page as it loads
            // $items.imagesLoaded().always(function (instance) {
            new Promise(function (resolve, reject) {
                let $content = $items.html();
                document.title = title;
                $('#page-wrapper').empty();
                $('#page-wrapper').append($content);
                resolve();
            }).then(function (result) {

                $('.site-branding a').blur();
                return new Promise((resolve, reject) => {
                    resolve();
                });

            }).then(function (result) {

                $('body').removeAttr('class').addClass(docClass);
                $('body').addClass('page-loaded');
                $('body').attr("data-themeify", docTheme);
                $('li.menu-item').removeClass('focus').blur();
                $('html').scrollTop(0);

                //reactivate js
                animateIn();
                slider();
                activateSplash();
                contactPage();

                $('a[href*="#"]')
                    // Remove links that don't actually link to anything
                    .not('[href="#"]')
                    .not('[href="#0"]')
                    .click(smoothScroll);

                return new Promise((resolve, reject) => {
                    resolve()
                });
            });
        });
    });


    if ('scrollRestoration' in history) {
        history.scrollRestoration = 'manual';
    }

    //change url when new page is loaded
    window.onpopstate = function (e) {
        window.location.href = window.location.href;
        // if(e.state){
        //     window.location.href = window.location.href;
        // }
        // console.log(e.state);
        // window.location.href = window.location.href;
    };

    //back to top
    // $('.to-top').on('click', function (e) {
    // 	$('html, body').animate({scrollTop: '0px'}, 700);
    // });

    //add active classes to menu when async is active
    $('#primary li').on('click', function (e) {
        $('#primary li').removeClass('current_page_item').removeClass('current-menu-item');
        $(this).addClass('current_page_item');

        if ($(window).width() < 1024 && 'ontouchstart' in window && !this.classList.contains('current_page_item')) {
            closeMenu();
        }
    });

    $('.site-branding a').on('click', function (e) {
        $('#primary li').removeClass('current_page_item').removeClass('current-menu-item');
    });