In the Messages app iCloud Drive.
The process for inviting someone to collaborate depends on the app. Here’s one way you might start a collaboration in a supported app:
Select the file you want to share, then tap After you invite participants in Messages, you can work on the project in the other app and return to the Messages conversation by tapping the Collaborate button in that app.When someone edits the file, you see updates at the top of the Messages thread. To return to the shared project and see changes, tap an update.Note: Your participants may need to accept your invitation or join the shared item before they can interact with it or see any updates.Tip: When you have your Files and Messages open in Split Screen, you can start a collaboration by dragging a file into the new message window and choosing Collaborate in the pop-up menu before sending.)
After you invite participants in Messages, you can work on the project in the other app and return to the Messages conversation by tapping the Collaborate button in that app.
When someone edits the file, you see updates at the top of the Messages thread. To return to the shared project and see changes, tap an update.
Note: Your participants may need to accept your invitation or join the shared item before they can interact with it or see any updates.
Tip: When you have your Files and Messages open in Split Screen, you can start a collaboration by dragging a file into the new message window and choosing Collaborate in the pop-up menu before sending.)
After you share your project, you see activity updates at the top of the Messages conversation whenever someone makes an edit.
Go to the conversation you want to manage, then tap the group icon at the top of the conversation to open details about the group’s conversation.
Tap the button showing the participants in the conversation, then do any of the following:
Add new participants: Scroll to the bottom of the list, tap Add Contact Have a group conversation in Messages on iPad