Apple Pencil markup not appearing after email recipient opens document
I have an iPad and an Apple Pencil. I receive documents to my work email and I’d like to be able to mark them up. However, whenever I write on those documents and send them to a recipient, the markup does not appear. I do not use Mail app in iOS. I use outlook and my work email through safari. How can I markup documents and ensure that it will still be there when the recipient opens the document?
iPad Pro Wi-Fi, iOS 11.2.6