Remove Reading Time from all but single posts in Reading Time WP

functions.php

<?php

function reading_time_remove_front_page() {
	if ( ! is_singular() ) {
		global $readingTimeWP;
		remove_filter('the_content', array($readingTimeWP, 'rt_add_reading_time_before_content'));
	}
}

add_action( 'wp', 'reading_time_remove_front_page' );