Hey there! Let me walk you through this question based on Apple's guidelines and what I've seen from other developers' real-world experiences:

First off, Apple does NOT explicitly force you to use a domain name for your app's server connections — direct IP addresses are technically allowed. That said, there are a few critical things you need to keep in mind:

• Review phase considerations: While using an IP won't automatically get your app rejected, Apple's review team might flag it for extra scrutiny. They could check if the IP's server is stable, compliant with regional data privacy rules (like GDPR or CCPA), and functioning as intended. As long as your server works properly and meets all other guidelines, you should be fine.
• Long-term maintenance headaches: This is the bigger practical issue. IP addresses can change (e.g., when you migrate servers, switch cloud providers, or your hosting provider reallocates IPs). If your app hardcodes an IP, you'll have to push a full app update to fix it — which means users have to download the new version to keep using your service. A domain name lets you update the DNS record to point to a new IP anytime, no app update needed. This is why using a domain is the industry best practice.
• HTTPS is non-negotiable: Whether you use a domain or an IP, Apple requires almost all network traffic from your app to use HTTPS. If you're using an IP, make sure your SSL certificate is specifically issued for that IP address — regular domain-validated certificates won't work here. Failing to set up HTTPS correctly (for either domain or IP) will definitely lead to a rejection.

To sum it up: You can use an IP address and get approved, but it's not a great long-term strategy. Domains are far more flexible and save you from unnecessary headaches down the line.

内容的提问来源于stack exchange，提问作者Sotiris Kaniras