Изменил путь хаба

AMessanger.API/Program.cs

@@ -28,6 +28,6 @@ app.MapControllers();
 
 app.UseSwagger().UseSwaggerUI();
 
-app.MapHub<ChatHub>("/hubs/chat");
+app.MapHub<ChatHub>(builder.Configuration.GetSection("Hubs")["MessangerPath"]!);
 
 app.Run();

AMessanger.API/appsettings.json

@@ -5,5 +5,8 @@
       "Microsoft.AspNetCore": "Warning"
     }
   },
-  "AllowedHosts": "*"
+  "AllowedHosts": "*",
+  "Hubs": {
+    "MessangerPath": "/messanger/chat"
+  }
 }