How to Hide Social proof testimonials and reviews by Repuso Admin Menus

function plt_hide_social_testimonials_and_reviews_widget_menus() {
	//Hide "Reviews".
	remove_menu_page('rw_widgets');
	//Hide "Reviews → Widgets".
	remove_submenu_page('rw_widgets', 'rw_widgets');
	//Hide "Reviews → Channels".
	remove_submenu_page('rw_widgets', 'rw_channels');
	//Hide "Reviews → Reviews".
	remove_submenu_page('rw_widgets', 'rw_reviews');
	//Hide "Reviews → Floating widget".
	remove_submenu_page('rw_widgets', 'pagewide_widget');
	//Hide "Reviews → Video guides".
	remove_submenu_page('rw_widgets', 'rw_overview');
}

add_action('admin_menu', 'plt_hide_social_testimonials_and_reviews_widget_menus', 11);

Where do I put this code?