Annotations that want to be shared are placed directly from the ebooks into the Dossier. Where which element can be divided is explained here.
The create your own page and press the export option Export-Option Button click on "Share My Page". The page is automatically added to the current dossier. Images and attachments can be sent with the application.
The Post-it can be added directly to the dossier in the pop-up window (second icon from the bottom right).