Following codes is used to trust the certificate, which not work in iPadOS 18.4: NSURLCredential *credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust]; completionHandler(NSURLSessionAuthChallengeUseCredential, credential); Here is the complete code for didReceiveAuthenticationChallenge: - (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential *credential))completionHandler { if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) { if ([challenge previousFailureCount] == 0) { SecTrustRef serverTrust = challenge.protectionSpace.serverTrust; CFErrorRef error; BOOL isCertificateValid = SecTrustEvaluateWithError(serverTrust, &error); CDVViewController* vc = (CDVViewController*)self.viewController; if(isCertificateValid) { NSURLCredential *credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust]; completionHandler(NSURLSessionAuthChallengeUseCredential, credential); } else { NSLog(@"ScanAndGo app certificate error: %@", error); CFDictionaryRef trustResultDict = SecTrustCopyResult(serverTrust); BOOL keyUsageFailure = NO; BOOL otherFailure = NO; ///... ///... There are some codes that check if the error is Key Usage error. // If it is key usage error, ignore. if(keyUsageFailure == YES && otherFailure == NO) { NSURLCredential *credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust]; completionHandler(NSURLSessionAuthChallengeUseCredential, credential); } else { completionHandler(NSURLSessionAuthChallengeCancelAuthenticationChallenge, nil); } } } else { completionHandler(NSURLSessionAuthChallengeCancelAuthenticationChallenge, nil); } } else { completionHandler(NSURLSessionAuthChallengeCancelAuthenticationChallenge, nil); } }