To collaborate on a shared document, you and the people you share with need any of the following:
A Mac with macOS 14.0 or later and Pages 14.3 or later
An iPhone with Collaborate on documents in Pages, Numbers, and Keynote.
When you’re not connected to the internet, you can continue to work on a document that’s shared with others. The next time you’re online, changes are uploaded to iCloud automatically. See Change a shared document’s settings in Pages on MacStop sharing a document in Pages on Mac