How to use cron on default console?

I’m confused with rancheros crontab service and regular crontab, as far as i read on docs builtin rancheros crontab service is just for running specific container in specific time, defined in cloud-config.

How can i run regular linux crontab to execute custom script?
Should i switch default console to persistent console to do this?

Trying running user container doing crontab but cant run host’s script because my crontab using docker commands, i.e : docker exec -ti database-server backup.sh

Anyone?

Thank you