How to Hide SMS Gateway Center Bulk SMS Sender Admin Menus

function plt_hide_sms_gateway_center_bulk_sms_sender_menus() {
	//Hide "SGCSMS".
	remove_menu_page('sgcsms');
	//Hide "SGCSMS → Send Bulk SMS".
	remove_submenu_page('sgcsms', 'sgcsms_send');
	//Hide "SGCSMS → Send Group SMS".
	remove_submenu_page('sgcsms', 'sgcsms_send_group_sms');
	//Hide "SGCSMS → Send SMS to Subscribers".
	remove_submenu_page('sgcsms', 'sgcsms_send_subscribers_sms');
	//Hide "SGCSMS → Groups".
	remove_submenu_page('sgcsms', 'sgcsms_groups');
	//Hide "SGCSMS → Delivery Report".
	remove_submenu_page('sgcsms', 'sgcsms_dlr');
	//Hide "SGCSMS → Message Templates".
	remove_submenu_page('sgcsms', 'sgcsms_msgTemplates');
	//Hide "SGCSMS → Incoming SMS".
	remove_submenu_page('sgcsms', 'sgcsms_shortcode');
	//Hide "SGCSMS → WP Subscriber Groups".
	remove_submenu_page('sgcsms', 'wpSubscriberGroups');
	//Hide "SGCSMS → WP Subscribers".
	remove_submenu_page('sgcsms', 'wpSubscribers');
	//Hide "SGCSMS → Sender Names".
	remove_submenu_page('sgcsms', 'sgcsms_sid');
	//Hide "SGCSMS → Credit Summary".
	remove_submenu_page('sgcsms', 'sgcsms_credSumm');
	//Hide "SGCSMS → Check Balance".
	remove_submenu_page('sgcsms', 'sgcsms_checkbalance');
	//Hide "SGCSMS → View Profile".
	remove_submenu_page('sgcsms', 'sgcsms_viewprofile');
	//Hide "SGCSMS → Change Password".
	remove_submenu_page('sgcsms', 'sgcsms_changepass');
	//Hide "SGCSMS → SMS Account Settings".
	remove_submenu_page('sgcsms', 'sgcsms_settings');
	//Hide "SGCSMS → OTP Settings".
	remove_submenu_page('sgcsms', 'sgcsms_otp_settings');
}

add_action('admin_menu', 'plt_hide_sms_gateway_center_bulk_sms_sender_menus', 11);
Where do I put this code?