functions.php

<?php

/**
 * Javascript for Load More
 *
 */
function be_load_more_js() {

	global $wp_query;
	$args = array(
		'nonce' => wp_create_nonce( 'be-load-more-nonce' ),
		'url'   => admin_url( 'admin-ajax.php' ),
		'query' => $wp_query->query,
	);
			
	wp_enqueue_script( 'be-load-more', get_stylesheet_directory_uri() . '/js/load-more.js', array( 'jquery' ), '1.0', true );
	wp_localize_script( 'be-load-more', 'beloadmore', $args );
	
}
add_action( 'wp_enqueue_scripts', 'be_load_more_js' );

/**
 * AJAX Load More 
 *
 */
function be_ajax_load_more() {

	check_ajax_referer( 'be-load-more-nonce', 'nonce' );
    
	$args = isset( $_POST['query'] ) ? $_POST['query'] : array();
	$args['post_type'] = isset( $args['post_type'] ) ? $args['post_type'] : 'post';
	$args['paged'] = $_POST['page'];
	$args['post_status'] = 'publish';

	ob_start();
	$loop = new WP_Query( $args );
	if( $loop->have_posts() ): while( $loop->have_posts() ): $loop->the_post();
		be_post_summary();
	endwhile; endif; wp_reset_postdata();
	$data = ob_get_clean();
	wp_send_json_success( $data );
}
add_action( 'wp_ajax_be_ajax_load_more', 'be_ajax_load_more' );
add_action( 'wp_ajax_nopriv_be_ajax_load_more', 'be_ajax_load_more' );

load-more.js

jQuery(function($){

	$('.post-listing').append( '<span class="load-more"></span>' );
	var button = $('.post-listing .load-more');
	var page = 2;
	var loading = false;
	var scrollHandling = {
	    allow: true,
	    reallow: function() {
	        scrollHandling.allow = true;
	    },
	    delay: 400 //(milliseconds) adjust to the highest acceptable value
	};

	$(window).scroll(function(){
		if( ! loading && scrollHandling.allow ) {
			scrollHandling.allow = false;
			setTimeout(scrollHandling.reallow, scrollHandling.delay);
			var offset = $(button).offset().top - $(window).scrollTop();
			if( 2000 > offset ) {
				loading = true;
				var data = {
					action: 'be_ajax_load_more',
					nonce: beloadmore.nonce,
					page: page,
					query: beloadmore.query,
				};
				$.post(beloadmore.url, data, function(res) {
					if( res.success) {
						$('.post-listing').append( res.data );
						$('.post-listing').append( button );
						page = page + 1;
						loading = false;
					} else {
						// console.log(res);
					}
				}).fail(function(xhr, textStatus, e) {
					// console.log(xhr.responseText);
				});

			}
		}
	});
});

Thanks for this did you call this function on your archive page be_ajax_load_more() ?