WP - Get link of page with specific template

get-template-page-url.php

<?php

function get_template_page_url( $template_name ) {

	$url   = null;
	$pages = new \WP_Query( array(
			'post_type'  => 'page',
			'meta_key'   => '_wp_page_template',
			'meta_value' => $template_name,
	) );

	// cycle through $pages here and either grab the URL
	// from the results or do get_page_link($id) with
	// the id of the page you want

	if ( isset( $pages[0] ) ) {
			$url = get_page_link( $pages[0]['id'] );
	}

	return $url;
}