ну конечно, кто будет коннект метод то вызывать? :/ а потом спрашиваю, почему же у меня ничего не работает? все, починила

SushiBarClientApp/APIClient.cs

@@ -9,9 +9,10 @@ namespace SushiBarClientApp
     {
         private static readonly HttpClient _client = new();
         public static ClientViewModel? Client { get; set; } = null;
+
         public static void Connect(IConfiguration configuration)
         {
-            _client.BaseAddress = new Uri("http://localhost:5262/");
+            _client.BaseAddress = new Uri(configuration["IPAddress"]);
             _client.DefaultRequestHeaders.Accept.Clear();
             _client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
         }

SushiBarClientApp/Program.cs

@@ -1,10 +1,9 @@
+using SushiBarClientApp;
 var builder = WebApplication.CreateBuilder(args);
-
 // Add services to the container.
 builder.Services.AddControllersWithViews();
-
 var app = builder.Build();
-
+APIClient.Connect(builder.Configuration);
 // Configure the HTTP request pipeline.
 if (!app.Environment.IsDevelopment())
 {
@@ -12,16 +11,11 @@ if (!app.Environment.IsDevelopment())
     // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
     app.UseHsts();
 }
-
 app.UseHttpsRedirection();
 app.UseStaticFiles();
-
 app.UseRouting();
-
 app.UseAuthorization();
-
 app.MapControllerRoute(
  name: "default",
  pattern: "{controller=Home}/{action=Index}/{id?}");
-
 app.Run();

SushiBarClientApp/SushiBarClientApp.csproj

@@ -6,6 +6,8 @@
     <ImplicitUsings>enable</ImplicitUsings>
   </PropertyGroup>
 
+ 
+
   <ItemGroup>
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
   </ItemGroup>

SushiBarRestApi/log4net.config

@@ -1,5 +1,7 @@
-<?xml version="1.0" encoding="utf-8" ?>
-<log4net>
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+
+	<log4net>
 		<appender name="RollingFile" type="log4net.Appender.RollingFileAppender">
 			<file value="logs/SushiBarRestApi.log" />
 			<appendToFile value="true" />
@@ -13,4 +15,6 @@
 			<level value="TRACE" />
 			<appender-ref ref="RollingFile" />
 		</root>
-</log4net>
+	</log4net>
+
+</configuration>