Call a minimal api from winform

Try below example

1) Add HttpClient to your WinForms Project: In your WinForms C# project, add a reference to System.Net.Http by right-clicking on the project, selecting "Manage NuGet Packages,"

2) Write Code to Call the Remote API: In your WinForms code, you can use the HttpClient class to call the remote API.

using System;
using System.Net.Http;
using System.Threading.Tasks;

namespace WinFormsApp
{
    public partial class Form1 : Form
    {
        private readonly HttpClient httpClient;

        public Form1()
        {
            InitializeComponent();
            httpClient = new HttpClient();
        }

        private async void btnCallApi_Click(object sender, EventArgs e)
        {
            try
            {
                string apiUrl = "http://REMOTE_MACHINE_IP/api/endpoint"; // Replace with the actual API URL

                HttpResponseMessage response = await httpClient.GetAsync(apiUrl);
                response.EnsureSuccessStatusCode();

                string responseBody = await response.Content.ReadAsStringAsync();

                // Process the response data here, display it on the WinForms UI, etc.
                textBoxResponse.Text = responseBody;
            }
            catch (HttpRequestException ex)
            {
                // Handle exceptions, e.g., API not accessible, server error, etc.
                MessageBox.Show($"Error: {ex.Message}", "API Call Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
    }
}