Open Integrations, pick your integration, and go to the widget settings.
You can edit the opening greeting, the line that asks for a name, the line that asks for a phone number, the waiting message, the line an agent's arrival prints, and the line sent when a chat is closed.
Two placeholders are substituted for you: write {name} for the visitor's name and {agent} for the agent who joined. Anything else is printed as typed.
Leave a line empty to skip it entirely. An empty closing line, for example, closes the chat silently.