Wp cron event is set but the function isn’t getting fired

by

I needed the hook name and not the function name so instead of this:

if ( ! wp_next_scheduled( 'do_this_in_an_hour' ) ) {
wp_schedule_single_event( time() + 40, 'do_this_in_an_hour' );
}

That:

if ( ! wp_next_scheduled( 'my_new_event' ) ) {
wp_schedule_single_event( time() + 40, 'my_new_event' );
}