Всегда в приложениях работающих с сетью стоит проверять наличие сети.

import Foundation
import SystemConfiguration

public class CheckInternet {
    class func isConnectedToNetwork() -> Bool {
        
        var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
        zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
        zeroAddress.sin_family = sa_family_t(AF_INET)
        
        let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) {
            $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {zeroSockAddress in
                SCNetworkReachabilityCreateWithAddress(nil, zeroSockAddress)
            }
        }
        
        var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
        if SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) == false {
            return false
        }
        
        let isReachable = flags == .reachable
        let needsConnection = flags == .connectionRequired
        
        return isReachable && !needsConnection
        
    }

}

if (CheckInternet.isConnectedToNetwork() == true) {
    ...  // есть интернет
    }
    else{
   ...  // у вас нет интернета
    }