Thank you for using GroupDocs.Annotation for .NET API.
Showcase are the example front-end to explain the API features and currently it working with PDF support only for exporting the document. However i am attaching image file where you can see how to change the front-end line of code to export document as Words (docx).
There are three major changes required to enable document export as words format instead of PDF file format. you need to modify code In " AnnotationService.cs" find the method Export
1. change this line " using (Stream inputDoc = _annotator.GetPdfFile(fileId).Stream)"
with using (Stream inputDoc = _annotator.GetFile(fileId).Stream)
2. update following line
var resultStream = _annotator.ExportAnnotationsToDocument(documentId, inputDoc, DocumentType.Pdf, userId);
var resultStream = _annotator.ExportAnnotationsToDocument(documentId, inputDoc, DocumentType.Words, userId);
3. final step is to change file extension
for further details, please have look on image attached with this thread. Kindly also note that front-end examples are open source its mean you can change/modify it as per your requirement without inform us.
If you will face any problem in exporting document as words, please feel free to ask.