docker postgres backup creates an empty file when run as a cron job

I'm trying to create a cronjob that creates db backups every night.

My crontab has the job: * * * * * /home/user/scripts/backup.sh (have it set to go off every min for testing)

In backup.sh, I have:

docker exec -it dbContainer pg_dump -U username -d dbName > /home/user/backups/testingBackup.sql

The file is always empty:

-rw-rw-r--  1 user user    0 Jul 14 08:39 testingBackup.sql

However, if I run the file on my own and type the command /home/user/scripts/backup.sh, it is not empty:

-rw-rw-r--  1 user user 30813 Jul 14 08:45 testingBackup.sql

I feel like it makes sense something is off on the permissions, but everything is done from the "user". I haven't done anything from root such as sudo crontab... sudo /home/user/backups/testingBackup.sql, etc.

I am confused as to why in one scenario, the resulting file is empty, and in the other, it is not.

Thanks for any help

đối với lệnh tôi có trong tệp sh: docker exec -it dbContainer pg_dump -U username -d dbName > /home/user/backups/testingBackup.sql

Nó đang chạy ở chế độ tương tác (-it). Nếu tôi xóa cái này, mọi thứ sẽ hoạt động (vì vậy lệnh là: docker exec dbContainer pg_dump -U tên người dùng -d dbName > /home/user/backups/testingBackup.sql