Receiving an unprompted one-time passcode (OTP) sent as an email or text should be a cause for concern as it likely means your credentials have been stolen.
ChatGPT users should be wary that their personal data might've been leaked online, following the dump of more than 100,000 ChatGPT account credentials on the dark web. As reported by The Hacker News and according to Singapore-based cybersecurity company Group-IB, the credentials for users that logged into ChatGPT ranges from its launch (in June 2022) through May 2023, meaning that it's still an ongoing event. The U.S., France, Morocco, Indonesia, Pakistan, and Brazil seem to have contributed the most users towards the stolen credentials.