python manage.py crontab add is not working on heroku server

[deeprajsinha]

Environment & Versions

• Operating system: heroku server
• Python:3.6.8
• Django:2.2.2
• django-crontab:0.7.1

Settings

• My django-crontab settings:

CRONJOBS = [
  ('0 0 * * *', 'vehicle_owner_booking.cron.my_scheduled_job'),
    ('55 23 * * *', 'vehicle_owner_booking.cron.subscription_ended_check'),
]

Details

when i running this crontab add command on heroku server its giving me error

• Output of crontab -l after running python manage.py crontab add.
  cannot found ‘/usr/bin/crontab’

so i checked inside usr/bin there is not crontab file present.
please help me.

[palfrey]

I'm guessing this means Heroku doesn't actually have cron installed. I'd note their documentation advises against it's use https://devcenter.heroku.com/articles/scheduled-jobs-custom-clock-processes