If you have found that the hyperlinks and outlines of an imported PDF document (i.e. a planner) are no longer usable outside the app, it might be because the document has been exported as a "flattened" PDF. "Flattened" means that everything becomes one layer and can't be edited, clicked or modified after exporting.
If you want to preserve these hyperlinks and outlines in an exported document, set the PDF Data Format to "Editable" in the Export Options.
Note: This article concerns pre-existing hyperlinks in an original PDF that you import to the app; they are not to be confused with hyperlinks you create in GoodNotes. The latter will be clickable in the exported PDF if you export the document in Flattened PDF Format.