ChatGPT offers a permanent Free plan for all users, while ChatGPT Plus trials...

https://fair-wiki.win/index.php/Can_I_Sign_Up_for_ChatGPT_Plus_at_$20_a_Month_and_Still_Get_a_Trial_Later%3F

ChatGPT offers a permanent Free plan for all users, while ChatGPT Plus trials are occasional offers for selected accounts. Some Plus trials may require a payment method and will auto-renew when the trial ends