ChatGPT offers a permanent Free plan with basic features available to all...

https://jaspersmasterinsights.opalvector.com/posts/how-do-i-activate-a-chatgpt-free-trial-in-the-mobile-app-if-i-m-eligible

ChatGPT offers a permanent Free plan with basic features available to all users. Occasionally, targeted Plus plan trials are offered, which may require a payment card and auto-renew unless canceled