Cron Help in Amazon Linux 2 EC2

It’s like not only Amazon Linux 2 I could not setup cron. I type

crontab -e

then

@reboot bash /home/ec2-user/abcd.sh

After Rebooting the EC2, this cron job doesn’t work. The same used to work in my Linode VM which had centos 8

Can someone please help me how can I setup cronjobs in Amazon Linux 2