How to Hide WP All Import Admin Menus

function plt_hide_wp_all_import_menus() {
	//Hide "All Import".
	remove_menu_page('pmxi-admin-home');
	//Hide "All Import → New Import".
	remove_submenu_page('pmxi-admin-home', 'pmxi-admin-import');
	//Hide "All Import → Manage Imports".
	remove_submenu_page('pmxi-admin-home', 'pmxi-admin-manage');
	//Hide "All Import → Settings".
	remove_submenu_page('pmxi-admin-home', 'pmxi-admin-settings');
	//Hide "All Import → Support".
	remove_submenu_page('pmxi-admin-home', 'pmxi-admin-help');
	//Hide "All Import → History".
	remove_submenu_page('pmxi-admin-home', 'pmxi-admin-history');
}

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

Where do I put this code?