I cant create my IKEv2 ConnectionApp

Hey to all

it's my first question here and I wish it helps me.

I want to create an IKEv2 VPN connection with swift, I tried to find a sample or a place for learning how to do it , but I can't find anything (I watched WWDC15 , but it doesn't work on swift 4.2 or more)

However I tried to create it with StackOverFlow's issues. but there is a bunch of question

- How can I prepare my cert Key for put it on NEVPNProtocolIKEv2() variable??? ( is .data(using: String.Encoding.utf8) enough???)

- Does cert's string need -----BEGIN CERTIFICATE----- and -----END CERTIFICATE----- ???

- How can I prepare my password like first question???

and finally here is my code, But it doesn't work 😟 :

import NetworkExtension
import UIKit
public final class IKEV2Connection {

    public func initProfile() {
        let vpnManager = NEVPNManager.shared()
        let server = "My server IP"
        let userName = "VPNUserName"
        let remoteIdentifier = server
        let cert = """
-----BEGIN CERTIFICATE-----
MIIFQjCCAyqgAwIBAgIIeB6GOr0OS80wDQYJKoZIhvcNAQEMBQAwPzELMAkGA1UE
......
U4Yqeart5YXLigwZ2cPOATEmv6SNIlp68eUVsPg4gvdYbe6Or0kBiScCKcH3
shfuLOjSTEIcedpQEy7b
-----END CERTIFICATE-----
""".data(using: .utf8)
        
        vpnManager.loadFromPreferences { (error) in
            
            if error != nil {
                print("Load config faild : \(error!.localizedDescription)")
                return
            }
            let weakP = vpnManager.protocolConfiguration as? NEVPNProtocolIKEv2
            var p: NEVPNProtocolIKEv2!
            if weakP != nil {
                p = weakP!
            } else {
                p = NEVPNProtocolIKEv2()
            }
            p.username = userName
            p.serverAddress = server
            p.certificateType = .RSA
            p.passwordReference = "VPNPassword".data(using: .utf8)
            p.sharedSecretReference = cert
            p.authenticationMethod = NEVPNIKEAuthenticationMethod.sharedSecret
            p.remoteIdentifier = remoteIdentifier
            p.useExtendedAuthentication = true
            p.disconnectOnSleep = true
            
            vpnManager.protocolConfiguration = p
            vpnManager.localizedDescription = "IPSec IKEv2 Demo3"
            vpnManager.isEnabled = true
            
            vpnManager.saveToPreferences(completionHandler: { (error) in
                if error != nil {
                    print("Save config failed : \(error!.localizedDescription)")
                }
            })
            do {
            try vpnManager.connection.startVPNTunnel()
            } catch let ex {
                print("error is \(ex)")
            }
        } 
    }   
}