Load custom jQuery in the footer that closes a popup on scroll

close_popup_on_scroll.php

<?php // Ignore this first line when copying to your child theme's functions.php file.

/**
 * Close a popup on a window scroll event.
 */
function close_popup_on_scroll() { ?>
 	<script type="text/javascript">
		jQuery(document).ready(function ($) {
			
				// Set up your constants.
    				const popupID = 630, // Change to your popup ID.
					scrlThresh = 3; // Adjust the scroll threshold if needed (0 means hide immediately).

				// Listen for after the popup opens.
				$(document).on('pumAfterOpen', `#pum-${popupID}`, function () {

					// While the popup is open, listen for scrolls.
			  		$(window).scroll(function() {
    						if ($(this).scrollTop() > scrlThresh) { // If this is true, we got a scroll hit!
							  PUM.close(popupID); // Close the popup.
							  $(window).off("scroll"); // Clean up.
							  console.log(`Popup ${popupID} says seeeee yaaaa 🙌🏼.`); // Debug only. Remove for production.
    						} // if
					}); // Scroll listener
					
				}); // After open listener
			
    		}); // jQuery
 	</script>
<?php }
add_action( 'wp_footer', 'close_popup_on_scroll', 500 ); // Load the script in the footer with a "late" priority.

// You can add the PHP code snippet to your child theme's <code>functions.php</code> file or with a third-party plugin such as <a href='https://wordpress.org/plugins/my-custom-functions/'>My Custom Functions</a>