How to use Quantum?

That’s not how you must use Quantum, follow their documentation on: https://hexdocs.pm/quantum/readme.htm

More details:

  • Quantum.add_job/2 is not a function, maybe what you mean is Quantum.Scheduler.add_job/2
  • Quantum.Scheduler.add_job/2 is not a function also, and yes a callback that should be defined by the modules that use @behaviour Quantum.Scheduler

My impression is that you may be confusing what the lib quantum really is. It’s not a job scheduler like, for example, sidekiq, what it does is something like what the command line tool cron does, scheduling recurrent executions.