How can I update the number of items in the shoppingcart in Blazor Server using LocalStorage?

Question

I have a shopping cart in Blazor Server project and I'm want to update the shoppingcart count everytime a product is added to the cart. I'm using localStorage to store the product. when I try to update the number of items in the cart I get an error:

System.InvalidOperationException: 'IJSInProcessRuntime not available'

Updating shopping cart in the Navigation bar:

<div class="top-row px-4">
    <a href="cart" >
        <span>
            <i class="bi bi-cart"></i> @GetCartItemsCount()
        </span>
    </a>
</div>

@code {
    [Inject] public ISyncLocalStorageService LocalStorage { get; set; }
    [Inject] public ICartService CartService { get; set; }

    protected override void OnInitialized()
    {
        CartService.OnChange += StateHasChanged;
    }

    private int GetCartItemsCount()
    {
        var cart = LocalStorage.GetItem<List<ShoppingCart>>(SD.ShoppingCart);
        return cart == null ? 0 : cart.Count;
    }

    public void Dispose()
    {
        CartService.OnChange -= StateHasChanged;
    }
}

In CartService I update the localstorage:

public class CartService : ICartService
{
    private readonly ILocalStorageService localStorage;
    public event Action OnChange;
    public CartService(ILocalStorageService localStorage)
    {
        this.localStorage = localStorage;
    }

    public async Task DecrementCart(ShoppingCart cartToDecrement)
    {
        var cart = await localStorage.GetItemAsync<List<ShoppingCart>>(SD.ShoppingCart);

        for (int i = 0; i < cart.Count; i++)
        {
            if (cart[i].ProductId == cartToDecrement.ProductId && cart[i].ProductVariantId == cartToDecrement.ProductVariantId)
            {
                if (cart[i].Count == 1 || cart[i].Count == 0)
                {
                    cart.Remove(cart[i]);
                }
                else
                {
                    cart[i].Count -= cartToDecrement.Count;
                }
            }
        }

        await localStorage.SetItemAsync(SD.ShoppingCart, cart);
        OnChange.Invoke();
    }

How can I update the numer of products in the shoppingcart? Thank you in advance.