How To Collaborate on a Document in Pages

Step 1 - Open "Document Options"

Select the title of your document in the top left of the screen to edit your document options.

If your document is not saved in iCloud, do so now. Or else, the remaining steps will not apply.

The document does not have to be complete before collaborating. All edits are synchronized with the collaborators.

Step 2 - Open "Document Sharing Options"