C# Initialize a Class with Array of another complex type

Question

Team, in C# don;'t know how to initialize below SiteExternalId Class with some dummy values, help me

public class SiteExternalId
{
public SiteExternalIdItem[] Item { get; set; }
}

public class SiteExternalIdItem
{
public ExternalTypeCd ExternalIdTypeCd { get; set; }

public string SiteNumber { get; set; }
}

public class ExternalTypeCd
{
public string ExternalIdTypeName { get; set; }

public string SiteCode { get; set; }
}