Ionic PSPDFKit how to save annotations

I am developing an application with ionic and I would like the user to be able to open a pdf (i use PSPDFKit plugin) and make the annotations there.
for the moment, I can open the pdf and make the annotations, but these annotations are not saved when we close the file, despite the fact that I activate the automatic saving in the options of opening my file.

here is my code

    options =  {  autosaveEnabled: true, 
                  annotationEditing: {
                  enabled: true, 
                  creatorName: 'Mr Kaplan'

      this.platform.ready().then(() => {
         const DOCUMENT ="ios")
         ? "Document.pdf"
         : "file:///android_asset/Document.pdf";

please how to save these annotations