https://www.notion.com/product/ai/use-cases/chat-about-anything allows you to type an ad hoc question and get an answer based on the setup sources that you have integrated into Notion. This feature would request would allow to you to start a chat conversation which ends up taking you to the https://www.notion.so/chat?t=<UNIQUE_CHAT_ID> without having to open Notion and typing a question.
