WordPress Add inline script for Javascript smooth scroll to anchor links

wordpress_add_inline_script_to_footer_for_smooth_scroll_to_anchor_links.php

function fn_add_inline_script_smooth_scroll_to_anchor_links() { 
	?>
	
	<script id="smooth_scroll_to_anchor_links">
		jQuery(function ($){
			
			const smooth_scroll_top_offset=-50;
			const smooth_scroll_animation_delay=1000;
			
			$('a[href*="#"]')
			// Remove links that don't actually link to anything
			.not('[href="#"]')
			.not('[href="#0"]')
			.click(function(event) {
				// On-page links
				if (
					location.pathname.replace(/^\//, '') == this.pathname.replace(/^\//, '') 
					&& 
					location.hostname == this.hostname
				){
					// Figure out element to scroll to
					var target = $(this.hash);
					target = target.length ? target : $('[name=' + this.hash.slice(1) + ']');
					
					// Does a scroll target exist?
					if (target.length) {
						// Only prevent default if animation is actually gonna happen
						event.preventDefault();
						$('html, body').animate({
							scrollTop: target.offset().top+smooth_scroll_top_offset
						},
						smooth_scroll_animation_delay,
						function() {
							// Callback after animation
							// Must change focus!
							var $target = $(target);
							$target.focus();
							if ($target.is(":focus")) { // Checking if the target was focused
								return false;
							} else {
								$target.attr('tabindex','-1'); // Adding tabindex for elements not focusable
								$target.focus(); // Set focus again
							};
						});
					}
				}
			});
		});
	</script>
	
	<?php
}
add_action('wp_footer', 'fn_add_inline_script_smooth_scroll_to_anchor_links');