Todo as Child Table in Event Doc Type


I have a requirement to Create multiple Todo Task for any Meeting Events created for Customer.
This I was trying to create by making child table of ToDo Doctype by Copying it and used same as Table in Event Doc type.
After this I am able to see Todo as Table in EVent but when I am entering the details then its not creating Todo and its not showing in Todo list.

This is my first post to Erpnext and first requirement mapping for my organisation.
Pardon me If I have created basic or silly query:roll_eyes: