With the document open, click to indicate the document is shared.
If you’re the owner of a document whose access is set to “Only invited people,” or if the owner of a shared document gives you permission to add people, you can invite more people to join the document using their Apple Account.
Note: If the document access is set to “Anyone with the link,” follow the instructions in the next task, Intro to collaboration in PagesStop sharing a document in Pages on Mac