Where it is: Settings → AI Behavior → Canned Responses. Not in the inbox, which is where everyone looks first — the library is a setting, the picker is in the chat.
Building the library
- Switch Enable canned responses on.
- Add a reply: a short title, which is what agents search by, and the full text that gets inserted.
- Up to fifty replies. Save.
Using one
In the handoff chat, open the canned-reply picker, type a word or two of the title, and the text drops into the composer — where you can still edit it before sending. Nothing is ever sent automatically.
The best source for this library is your own inbox. After a week of live chats, the three answers you have retyped most are the three that belong here.