How to Hide Blockons Admin Menus

function plt_hide_blockons_menus() {
	//Hide the "Settings → Blockons Settings" menu.
	remove_submenu_page('options-general.php', 'blockons-settings');
	//Hide the "Settings → Upgrade" menu.
	remove_submenu_page('options-general.php', 'blockons-settings-pricing');
}

add_action('admin_menu', 'plt_hide_blockons_menus', 1000000000);

Where do I put this code?