To access your message settings, tap your profile photo at top left, and then tap Message under Settings.
Message settings for mobile
Show link previews: Toggle on to enable preview of the page each time a link is sent in a message thread.
Display flags for external guests: Toggle on to show hints and visual cues in conversations with guests outside your company.
Shortcut for external keyboards: Select your preferred shortcut for sending a message or inserting a new line of text when pressing enter using an external keyboard (iOS only).