Buttons and menus are named exactly as the app shows them.
Steps
Export everything
Export data copies all of your data as text, which you can paste into a file and keep.
Where: Settings › Storage & offline › Export data
Bring it back
Paste an export into Import data to restore it.
Where: Settings › Storage & offline
Export one note or sheet
Export a note from the note itself, and a sheet as CSV.
Keep your conversations
Export the assistant’s conversations from its settings.
Where: Agent › Settings › Conversations