MessageExtension returned a NSURLErrorDomain when requesting the server.

I'm developing iOS message extension to filter the unwanted message. The plugin needs a help from server to filter the message. However, the iOS returned the error NSURLErrorDomain while requesting the server.

Based on the official document, I defined the key/value pair in Info.plist of Message Extension. ILMessageFilterExtensionNetworkURL has value: https://mydomain.io/api/v1/sms

The code that I test the request as follows:

let url = URL(string: "https://mydomain.io/api/v1/sms")!

var request = URLRequest(url: url)
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.setValue("you-value-goes-here", forHTTPHeaderField: "X-API-KEY")


let task = URLSession.shared.dataTask(with: request) { data, _, error in
    if let data = data {
        print(data)
    } else if let error = error {
        print("Http failed: \(error)")
    }
}

task.resume()

From the stack trace, as far as I known, there is a problem with dns resolution. Why does this happened and how to fix this case?

[0]	(null)	"_kCFStreamErrorCodeKey" : Int32(-72000)	
[1]	(null)	"NSUnderlyingError" : domain: "kCFErrorDomainCFNetwork" - code: 18446744073709550613	
[2]	(null)	"_NSURLErrorFailingURLSessionTaskErrorKey" : "LocalDataTask <B496A974-7009-4FCE-BF45-FEC07BA1E8DF>.<1>"	
[3]	(null)	"_NSURLErrorRelatedURLSessionTaskErrorKey" : 1 element	
[4]	(null)	"NSLocalizedDescription" : "A server with the specified hostname could not be found."	

Thanks