React front is on 3000 and my as.net backend on 5000. React part has product definition and data fetching from localhost:5000/api and accesing data by prevState in AddProduct function. Based on the tutorial, I have cors to program.cs but I cannot make it work. When running the application, I get This localhost page can’t be found error 401.

Product.tsx

export interface Product {
  id: number;
  name: string;
  description: string;
  price: number;
  pictureUrl: string;
  type?: string;
  brand: string;
  quantityInStock?: number;
}

App.tsx

import { useEffect, useState } from 'react';
import { Product } from './product';

function App() {
  const [products,setProducts] = useState<Product[]>([]);

  useEffect(() => {
    fetch('htttp://localhost:5000/api/products')
      .then(response => response.json())
      .then(data => setProducts(data))
  },[])

  function addProduct() {
    setProducts(prevState => [...prevState,
      {
        id: prevState.length + 101,
        name: "product" + (prevState.length + 1),
        price: (prevState.length * 100) + 100,
        brand: 'some brand',
        description: 'some description',
        pictureUrl: 'http://picsum.photos/200',
      }])
}
 
  return (
    <div className="app">
      <h1>RESTORE</h1>
      <ul>
        {products.map(product=>(
          <li key={product.id}>{product.name} - {product.price}</li>
        ))}
      </ul>
      <button onClick={addProduct}>Add product</button>
    </div>
  );
}

export default App;

Program.cs

using API.Data;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Migrations.Operations;

internal class Program
{
    private static void Main(string[] args)
    {
        var builder = WebApplication.CreateBuilder(args);
        builder.Services.AddControllers();
        builder.Services.AddEndpointsApiExplorer();
        builder.Services.AddSwaggerGen();
        builder.Services.AddDbContext<StoreContext>(opt =>
        {
            opt.UseSqlite(builder.Configuration.GetConnectionString("DefaultConnection"));
        });
        builder.Services.AddCors();
        var app = builder.Build();

        // Configure the HTTP request pipeline.
        if (app.Environment.IsDevelopment())
        {
            app.UseSwagger();
            app.UseSwaggerUI();
        }
        app.UseCors(opt =>
        {
            opt.AllowAnyHeader().AllowAnyMethod().WithOrigins("http:/localhost:3000");

        });
        app.UseAuthorization();
        app.MapControllers();

        var scope = app.Services.CreateScope();
        var context = scope.ServiceProvider.GetRequiredService<StoreContext>();
        var logger = scope.ServiceProvider.GetRequiredService<ILogger<Program>>();
        try
        {
            context.Database.Migrate();
            DBInitializer.Initilize(context);
        }
        catch (Exception ex)
        {

            logger.LogError(ex, "A problem occurred during migration");
        }
        app.Run();
    }
}

I have tried to check if my Cors correctly writen anf if referenced local port are correct.