https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.printing.printdocument.setpreviewpagecount?view=windows-app-sdk-1.8
PrintDocument.SetPreviewPageCount(Int32, PreviewPageCountType) Method (Microsoft.UI.Xaml.Printing)...
Sets the number of pages prepared for print preview and added to the print list.
methodmicrosoftuixamlprinting