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

https://zulu-wiki.win/index.php/Why_Does_ChatGPT_Plus_Cost_$20_a_Month_After_the_Trial_Ends%3F

ChatGPT offers a permanent Free plan available to all users with basic access. Occasionally, paid Plus plan trials are offered as targeted promotions. Some trials require a credit card and auto-renew into a paid subscription when they end