ChatGPT offers a permanent Free plan available to all users. Occasionally,...

https://astro-wiki.win/index.php/How_to_Avoid_Surprise_Charges_on_ChatGPT_Trials

ChatGPT offers a permanent Free plan available to all users. Occasionally, targeted promotions provide a limited free trial for the Plus plan, which may require a payment card and auto-renews after the trial ends