Swift:
HTTP-Anfragen mit Basisauthentifizierung senden

import Foundation

let username = "benutzer"
let password = "passwort"
let loginString = "\(username):\(password)"
if let loginData = loginString.data(using: .utf8) {
    let base64LoginString = loginData.base64EncodedString()

    var request = URLRequest(url: URL(string: "https://beispielapi.de/daten")!)
    request.httpMethod = "GET"
    request.setValue("Basic \(base64LoginString)", forHTTPHeaderField: "Authorization")

    let session = URLSession.shared
    session.dataTask(with: request) { data, response, error in
        guard let data = data, error == nil else { print(error?localizedDescription ?? "Unbekannter Fehler"); return }
        if let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode == 200 {
            // Verarbeite die Antwort
            print(String(data: data, encoding: .utf8) ?? "Antwort konnte nicht verarbeitet werden")
        } else {
            print("HTTP Status Code: \((response as? HTTPURLResponse)?.statusCode ?? -1)")
        }
    }.resume()
}