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

https://eduardosnicechat.publishlane.com/posts/does-chatgpt-have-a-referral-link-trial-i-can-ask-a-friend-for

ChatGPT offers a permanent Free plan with basic access for all users. Occasionally, targeted promotions provide a free trial of ChatGPT Plus, which may require a payment card and auto-renews when the trial ends