Hello Sanjitha,
Please check that your scheduler is enable in environment.
navigate to the Environments section in the Mendix Developer Portal, select the specific environment, and then go to the Model Options tab-"Scheduled Events"-Enable that and restart the application.
If you are running in the free sandbox, scheduled events are not available. You would need to upgrade to a paid environment to use scheduled events.
https://docs.mendix.com/developerportal/deploy/mendix-cloud-deploy/#free-app
I hope this helps.