private static AndroidJavaObject sHttpDnsObj;
 public static void Init() {
     AndroidJavaClass unityPlayerClass = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
     if (unityPlayerClass == null) {
         return;
     }	
     AndroidJavaObject activityObj = unityPlayerClass.GetStatic<AndroidJavaObject>("currentActivity");
     if (activityObj == null) {
         return;
     }
     AndroidJavaObject contextObj = activityObj.Call<AndroidJavaObject>("getApplicationContext");
     // Initialize HTTPDNS
     AndroidJavaObject httpDnsClass = new AndroidJavaObject("com.tencent.msdk.dns.MSDKDnsResolver");
     if (httpDnsClass == null) {
         return;
     }
     sHttpDnsObj = httpDnsClass.CallStatic<AndroidJavaObject>("getInstance");
     if (sHttpDnsObj == null) {
         return;
     }
     
     // For v4.0.0 or later (recommended). For more information, see Android SDK
     AndroidJavaObject dnsConfigBuilder = new AndroidJavaObject("com.tencent.msdk.dns.DnsConfig$Builder");
     dnsConfigBuilder.Call<AndroidJavaObject>("dnsId", "XXX");
     dnsConfigBuilder.Call<AndroidJavaObject>("dnsIp", "XXX");
     dnsConfigBuilder.Call<AndroidJavaObject>("dnsKey", "XXX");
     // Other configuration information
     AndroidJavaObject dnsConfig = dnsConfigBuilder.Call<AndroidJavaObject>("build");
      
     sHttpDnsObj.Call("init", contextObj, dnsConfig);
     
     // For a version earlier than v4.0.0
     sHttpDnsObj.Call("init", contextObj, appkey, dnsid, dnskey, dnsIp, debug, timeout);
 }

// We recommend you perform this operation on a child thread or with Coroutine
// Note that you need to call the `AttachCurrentThread` and `DetachCurrentThread` functions before calling the `getAddrByName` API on the child thread 
public static string GetHttpDnsIP(string url) {
    string ip = string.Empty;
    AndroidJNI.AttachCurrentThread(); // You need to add this when calling the `getAddrByName` API on the child thread
    // Get the IP configuration set
    string ips = sHttpDnsObj.Call<string>("getAddrByName", url);
    AndroidJNI.DetachCurrentThread(); // You need to add this when calling the `getAddrByName` API on the child thread
    if (null != ips) {
        string[] ipArr = ips.Split(';');
        if (2 == ipArr.Length && !"0".Equals(ipArr[0]))
        ip = ipArr[0];
    }
    return ip;
}

 UnityWebRequest www = UnityWebRequest.Get(url);
 www.certificateHandler = new CertHandler();
 yield return www.SendWebRequest();
   
 // CertHandler is a custom certificate handler class that overrides the ValidateCertificate method to implement custom certificate validation logic. 
 public class CertHandler : CertificateHandler
 {
     protected override bool ValidateCertificate(byte[] certificateData)
     {
         X509Certificate2 certificate = new X509Certificate2(certificateData);
         X509Certificate2Collection collection = new X509Certificate2Collection();
         collection.Import(Application.dataPath + "/Certificates/server.cer");
         return certificate.Issuer == collection[0].Issuer;
     }
 }