how do I run cronjob in Alpine container? I am currently running ckan container and this are the code I have tried to run cronjob

The cronjob that I want to run is just to delete a file inside a specific folder

1. I have used python-crontab and here is my code
   this isn’t working, I tried the code to schedule, but it did not trigger

from crontab import CronTab
cron = CronTab()
job = cron.new(command='/usr/bin/find /srv/app -name "*.zip" -type f -mmin +1 -mmin -120 -delete')

2. I have tried the rq-scheduler
   I wanted to try to trigger this scheduler every 30 seconds, but only trigger once after the application loads

from rq_schuleder import Scheduler

def myjob():
  print("ssssfdv")

redis_conn = Redis(host="redis", port=6379)
scheduler = Scheduler(connection=redis_conn)
scheduler.schedule(
  scheduled_time=datetime.utcnow(),
  func=myjob
  interval=30
)

3. Using the ckan background (I am not sure if I did it correctly)
   triggered only once after the application loads, and did not trigger after 1 seconds.

import ckan.lib.jobs as jobs 
jobs.enqueue(fn=myjob(), title="test",queue="testingqueue", rq_kwargs={"timeout":1})

4. I tried to use the Dockerfile to trigger the cron job, but it is not working too
   here is the code I put in the DockerFile
   RUN echo ‘*/1 * * * * /srv/app/cron.py’ > /etc/crontabs/root

inside the cron.py

> import os 
> os.remove("<the path to the file I want to delete>")

I wanted to create a cronjob to cleanup a particular folder on midnight only. The execution is once per day.
Can someone pls help me?? I am not sure if I did any of the implementation wrongly.