Since updating to version 1.5.19 I get an error message

Good morning,
I just updated to breadcrumbs 1.5.19 and the new wordpress build 5.7.1 and I now get an error message in the admin dashboard:

constant post_grid_plugin_url - assumed 'post_grid_plugin_url' (this will throw an Error in a future version of PHP) in /code/wp-content/plugins/breadcrumb/breadcrumb.php on line 76

Is there a way to eliminate this conflict? The line in question is:

wp_register_script('jquery.lazy', post_grid_plugin_url.'assets/admin/js/jquery.lazy.js', array('jquery'));