Some document types like Microsoft Word, Excel, OpenOffice Text and Spreadsheet may contain comments. Your requirement to include or exclude the comments in output representation of the document may vary in different situations. GroupDocs.Viewer Cloud enables you to control the rendering of document comments. By default, comments are not rendered into the output document. The API provides RenderComments property of HtmlOptions (or JpgViewOptions, or PdfOptions) class that enables rendering of comments....Please get your Client Id and Client Secret from https://dashboard...place Client Id in "client_id" and Client Secret in "client_secret"...