To cancel your ChatGPT subscription, be sure to do it through the same billing...

https://iris-wiki.win/index.php/What_if_the_Stripe_Billing_Portal_Never_Opens_for_ChatGPT%3F

To cancel your ChatGPT subscription, be sure to do it through the same billing channel you used to subscribe—whether that’s the web via Stripe, Apple App Store, Google Play, Business account, or API