This week Heroku announced that they will stop offering free plans and will begin to close free dynos across accounts. It's a shame, as many students and devs first starting out rely on Heroku's free tier services. There are alternatives though, fortunately.
"Starting October 26, 2022, we will begin deleting inactive accounts and associated storage for accounts that have been inactive for over a year. Starting November 28, 2022, we plan to stop offering free product plans and plan to start shutting down free dynos and data services."