How to fix Unhandled exception rendering component: The JSON value could not be converted to System.Int32.

When I use the PlaceOrder method, it causes this error. The version is 8.0. Thank you.

async Task PlaceOrder()
    {
        isSubmitting = true;
        var response = await HttpClient.PostAsJsonAsync(NavigationManager.BaseUri + "orders", OrderState.Order);
        var newOrderId = await response.Content.ReadFromJsonAsync<int>();
        OrderState.ResetOrder();
        NavigationManager.NavigateTo("/");
    }