Open the document, then click on the share icon-it looks like a square with an arrow on top. You should see an option to “create pdf” click on it. When you go to save it try to save it to DropBox. If it won’t let you save it there, then just choose another option. Then go into DropBox and use the imprt option and find the file under the folder that you saved it to. If you do not see an option to convert to pdf just download the free app from the App Store called “PDF Converter.”