Hi,

By using an automated action, you can send the notification.

1- Create an automated action like,

2- Add action as needed.

For more information, refer to the following.

Automated action:- 

* https://www.cybrosys.com/blog/how-to-configure-automated-actions-in-odoo-18

* https://www.odoo.com/documentation/18.0/applications/studio/automated_actions.html

Display Notification:- 

* https://www.cybrosys.com/blog/how-to-create-display-notification-in-odoo-16

* https://www.youtube.com/watch?v=AJzCM2-OMfY

Hope it helps

You could set up an automation rule that sends a notification upon create of crm.lead.

See https://www.odoo.com/documentation/18.0/applications/studio/automated_actions.html