How to Hide the "WP Monero Miner" Admin Menu

function plt_hide_wp_monero_miner_using_coin_hive_menus() {
	//Hide the "Settings → WP Monero Miner" menu.
	remove_submenu_page('options-general.php', 'wp-coin-hive');
}

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

Where do I put this code?