Scheduled Events with a serverless framework

I am using a NextJS and Firebase for my app. Since NextJS is event-driven, I can’t seem to figure out how to perform scheduled tasks. For example, a user has a subscription which expires in a month. How do I set up a scheduled task that updates the database regarding the expiration of the user’s subscription after a month without the need of an event triggering it.

I have looked into Github Actions to schedule cron jobs, but that is not an ideal solution since I would need to create several cron jobs for each user.

Please help!