ChatGPT offers a permanent Free plan available to everyone, which includes...

https://front-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 everyone, which includes basic features at no cost. Occasionally, targeted users may receive Plus plan trials, some requiring a payment card and auto-renewal once the trial ends