I am trying to retrieve a distinct list of brands from my Product table using Ardalis.Specification in a .NET application. But seems like Distinct doesn't work.

public class GetDistinctManufacturersSpec : Specification<Product, string>
{
    public GetDistinctManufacturersSpec(uint companyId)
    {
        _ = Query.Where(x => x.CompanyId == companyId && !string.IsNullOrEmpty(x.Manufacturer))
        _ = Query.Select(x => x.Manufacturer).Distinct(); 
             
    }
}

It says ISpecification<Product, string> doesn't contain a defination for 'Distinct'