Rotate pages of pdf using merger api

Hello all I have a pdf with some pages in portrait and some in landscape, now I want to change the pages which is in landscape into portrait mode, I used groupdocs merger

OrientationOptions orientationOptions = new OrientationOptions(OrientationMode.Landscape, new int[] { 1 });
                using (Merger merger = new Merger(documentPath))
                {
                    merger.ChangeOrientation(orientationOptions);
                    merger.Save(documentPath);
                }

above is my code to rotate pdf page in portrait mode, I tried this code on 20.4 and 21.7 version of groupdocs merger but I am getting the error of

Requested ChangeOrientation operation for ‘Pdf’ document type is not supported on the below line

merger.ChangeOrientation(orientationOptions);

@Niteen_Jadhav

This issue is reproduced at our end. Hence, we’ve logged it in our internal issue tracking system with ID MERGERNET-1174. It’ll be now further investigated and you’ll be notified about the outcomes.