This depends directly on how the proxy server works. Some of them do not require any authorization at all, others require username and password for access, and others require you to view ads and so on. Which option will be used depends directly on the service that provides access to the proxy server.

To find an element by its HTML code in Selenium, you can use the ExecuteScript method to execute JavaScript code that returns the element corresponding to the provided HTML code. Here's an example of how to do this using C#:

Install the required NuGet packages:

Install-Package OpenQA.Selenium.Chrome.WebDriver -Version 3.141.0
Install-Package OpenQA.Selenium.Support.UI -Version 3.141.0

Create a method to find an element by its HTML code:

using OpenQA.Selenium;
using OpenQA.Selenium.Support.UI;
using System;
using System.Text.RegularExpressions;

public static IWebElement FindElementByHtml(this IWebDriver driver, string htmlCode)
{
    // Execute JavaScript to create a new element with the provided HTML code
    var script = $@"var div = document.createElement('div'); div.innerHTML = arguments[0]; document.body.appendChild(div); return div.children[0];";
    var element = (IWebElement)driver.ExecuteScript(script, htmlCode);

    // Remove the created element from the DOM
    driver.ExecuteScript("document.body.removeChild(document.body.children[document.body.children.length - 1]);");

    return element;
}

Use the FindElementByHtml method in your test code:

using OpenQA.Selenium;
using System;

namespace SeleniumFindElementByHtmlExample
{
    class Program
    {
        static void Main(string[] args)
        {
            // Set up the WebDriver
            IWebDriver driver = new ChromeDriver();
            driver.Manage().Window.Maximize();

            // Navigate to the target web page
            driver.Navigate().GoToUrl("https://www.example.com");

            // Find an element by its HTML code
            IWebElement element = driver.FindElementByHtml(@"
                

                    
Example Heading
                    
Example paragraph text.
                
");

            // Perform any additional actions as needed

            // Close the browser
            driver.Quit();
        }
    }
}

In this example, we first create a method called FindElementByHtml that takes an IWebDriver instance and a string containing the HTML code as input. Inside the method, we use the ExecuteScript method to execute JavaScript code that creates a new element with the provided HTML code, appends it to the document body, and returns the created element.

We then remove the created element from the DOM using another ExecuteScript call. The method returns the created element as an IWebElement.

In the test code, we set up the WebDriver, navigate to the target web page, and use the FindElementByHtml method to find an element by its HTML code. After finding the element, you can perform any additional actions as needed.

Remember to replace the HTML code in the FindElementByHtml method call with the actual HTML code you want to use.

To test a UDP sender, you can create a mock UDP client that simulates the behavior of the real UDP client. This way, you can test the sending functionality without actually sending data over the network.

Here's an example of how to create a mock UDP client and write a unit test for a UDP sender in C#:

1. Create a mock UDP client class:

public class MockUdpClient : IDisposable
{
    private readonly byte[] _receivedBytes;
    private int _receivedCount;

    public MockUdpClient()
    {
        _receivedBytes = new byte[1024];
        _receivedCount = 0;
    }

    public void Receive(byte[] data, int length)
    {
        Array.Copy(data, _receivedBytes, length);
        _receivedCount++;
    }

    public void Dispose()
    {
        // Clean up any resources if needed
    }

    public int ReceivedCount => _receivedCount;

    public byte[] ReceivedData => _receivedBytes;
}

2. Modify the UDP sender to accept a mock UDP client:

public class UdpSender
{
    private readonly MockUdpClient _mockUdpClient;

    public UdpSender(MockUdpClient mockUdpClient)
    {
        _mockUdpClient = mockUdpClient;
    }

    public void SendData(string data)
    {
        var bytes = Encoding.ASCII.GetBytes(data);
        _mockUdpClient.Receive(bytes, bytes.Length);
    }
}

3. Write a unit test for the UDP sender:

[TestClass]
public class UdpSenderTests
{
    [TestMethod]
    public void TestSendData()
    {
        // Arrange
        var mockUdpClient = new MockUdpClient();
        var udpSender = new UdpSender(mockUdpClient);
        var data = "Test data";

        // Act
        udpSender.SendData(data);

        // Assert
        Assert.AreEqual(1, mockUdpClient.ReceivedCount);
        CollectionAssert.AreEqual(Encoding.ASCII.GetBytes(data), mockUdpClient.ReceivedData);
    }
}

In this example, we created a MockUdpClient class that simulates the behavior of a real UDP client. The UdpSender class now accepts a MockUdpClient as a parameter, allowing us to test the sending functionality without actually sending data over the network.

Finally, we wrote a unit test using the TestClass and TestMethod attributes from the Microsoft.VisualStudio.TestTools.UnitTesting namespace. The test method TestSendData checks whether the UdpSender class sends data correctly by comparing the received data with the expected data.

In the "Settings" of any Android smartphone there is a "VPN" item. And there you can manually specify the parameters of the proxy, through which the connection to the Internet will be made. There, some of the programs also import ready-made scripts for proxy connections.

To connect your iPhone to a proxy server, follow these steps:
Open the "Settings" section. Go to the "Wi-Fi" tab. Next to your access point, click on the "i" button. Click on "Proxy settings". Use the manual setting and specify the proxy data. To specify a login and password from the proxy you should enable the "Authentication" option. Save the settings.