Where it is: Design → Widgets — the Home Screen and Proactive Teasers cards.
Home screen
Instead of opening straight into an empty chat, the widget can open onto a small landing view: a greeting, an availability card, suggested questions and a button into the conversation. It reliably increases the number of people who start one.
Proactive teasers
Small bubbles that appear beside the closed launcher after a delay. They can be sequenced, targeted at specific URLs, and dismissed individually — and a dismissal is remembered, so nobody is nagged twice.
Use teasers sparingly. One well-timed message on a pricing page works; three on every page is the reason people hate chat widgets.