> For the complete documentation index, see [llms.txt](https://payment.excoinz.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://payment.excoinz.com/firewalls-and-security.md).

# Firewalls and security

## Firewall settings

A firewall is a security system that prevents external, untrusted networks from accessing your internal network. It can do this by filtering incoming requests from specific ports or IPs, requiring user authentication, proxies, and network address translation (NAT).

## Allow port numbers

1. Allow port 443 for API requests
2. Allow webhook URL ports

{% hint style="info" %}
You can request a callback URL for webhook registration by excoinz email.

* [partner@excoinz.com](mailto:partner@excoinz.com?subject=Excoinz%20Inquiry\&body=)
  {% endhint %}

## Add an IP access control list

If your game company's server categorizes traffic with an IP [Access Control List (ACL)](https://en.wikipedia.org/wiki/Access-control_list) to allow or deny traffic, please allow Excoinz ExPay's IP address.

Allow access to the following IPs and inbound requests will be sent as normal.

* 13.229.255.195

## HTTP Protocol

The Excoinz ExPay API must be called over HTTPS.

[HTTPS](https://en.wikipedia.org/wiki/HTTPS) is a secured version of HTTP. Because data sent to and from HTTP is unencrypted plaintext, it can leak personal information, so you should use HTTPS, a more secure protocol that protects your customers' payment information and personal data.