Cannot ask for network permission when sending UDP package to an IP Address

[lxylxy123456]

Refer to this question and my project

When I send a UDP package to an IP Address, the simulator accepts the package, but when testing on a real device, send method returns "Optional(SwiftSocket.SocketError.unknownError)". I have to use a domain name (like "github.com") first to get authorization, and then I can send packages to other IP addresses.