Customize Annotation Saving Permissions in Flutter
PSPDFKit can write annotations into a PDF under the following conditions:
The PDF isn’t password protected. (Note: Some PDFs are protected with an empty password, just to ensure they can’t be modified. PSPDFKit will auto-unlock them but can’t add annotations to them.)
The PDF must be in a writable location. Ensure you copy documents to the documents folder to make them writable.
The PDF must be valid according to the Adobe PDF specification. Some PDFs are broken but still work somewhat, so PSPDFKit can render the content. If PSPDFKit detects a mismatch in the object tree or is unable to find objects, annotation saving will be stopped, since there would be a risk of damaging the document.
PSPDFKit will save changed, created, or deleted annotations to a document on several occasions. Learn more about these triggers in the Auto Save guide.