How to Hide Chainium - Web3 Wallet Authenticator, Blockchain Connector Admin Menus

function plt_hide_chainium_menus() {
	//Hide "BeycanPress Plugins".
	remove_menu_page('beycanpress-plugins');

	//Hide "Chainium".
	remove_menu_page('chainium');
	//Hide "Chainium → User List".
	remove_submenu_page('chainium', 'chainium');
	//Hide "Chainium → Settings".
	remove_submenu_page('chainium', 'chainium-settings');
}

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

Where do I put this code?