avalonia/AvaloniaApplication1/Models/ApiService.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Json;
using System.Text;
using System.Threading.Tasks;

namespace AvaloniaApplication1.Models
{
    public class ApiService
    {
        private readonly HttpClient _httpClient;
        public ApiService()
        {
            _httpClient = new HttpClient();
            _httpClient.BaseAddress = new Uri("https://localhost:7241/");
        }

        public async Task<T?> GetAsync<T>(string endpint)
        {
            return await _httpClient.GetFromJsonAsync<T>(endpint);
        }
    }
}