No overload for 'Search1' matches delegate 'Func'

I am learning about MudAutocomplete code from https://mudblazor.com/components/autocomplete#api and copy code to run test but I found error 'No overload for 'Search1' matches delegate 'Func<string, CancellationToken, Task<IEnumerable<string>>>''

<MudGrid><MudItem xs="12" sm="6" md="4"><MudAutocomplete T="string" Label="US States" @bind-Value="value1" SearchFunc="@Search1"  Variant="Variant.Outlined" /></MudItem></MudGrid>

@code {    private string value1;    private string[] states =    {"Alabama", "Alaska", "American Samoa", "Arizona","Arkansas", "California", "Colorado", "Connecticut","Delaware", "District of Columbia", "Federated States of Micronesia","Florida", "Georgia", "Guam", "Hawaii", "Idaho","Illinois", "Indiana", "Iowa", "Kansas", "Kentucky","Louisiana", "Maine", "Marshall Islands", "Maryland","Massachusetts", "Michigan", "Minnesota", "Mississippi",    };    private async Task<IEnumerable<string>> Search1(string value)    {        // In real life use an asynchronous function for fetching data from an api.        await Task.Delay(5);        // if text is null or empty, show complete list        if (string.IsNullOrEmpty(value))            return states;        return states.Where(x => x.Contains(value, StringComparison.InvariantCultureIgnoreCase));    }}

How can I find solution ? Thank you.