Вот как я это сделал.
function clearNotes(){
var presentation = SlidesApp.getActivePresentation();
var presentationId = presentation.getId();
var slides = presentation.getSlides();
var requests = [];
slides.forEach(function(slide, i) {
var slideNote = Slides.Presentations.Pages.get(presentationId, slide.getObjectId());
var slideNoteId = JSON.parse(slideNote).slideProperties.notesPage.notesProperties.speakerNotesObjectId;
var slideNotesPage = JSON.parse(slideNote).slideProperties.notesPage;
var shapeText = slideNotesPage.pageElements[1].shape.text;
if(shapeText != undefined){
requests.push({
deleteText: {objectId: slideNoteId,textRange:{type: 'ALL'}}
});
}
})
if(requests.length > 0){
var batchUpdateResponse = Slides.Presentations.batchUpdate({requests: requests}, presentationId);
}
}
Надеюсь, это поможет.