Why do it: Making an advanced attribute mandatory ensures that the customer must select or enter a value before adding the product to the cart.
Procedure
1. Access the Advanced Attributes configuration section.
2. Locate the block related to the field you want to make mandatory.
3. Within this block, scroll until you find the option:
4. Check the box next to Make mandatory.
5. Save the changes (usually via a Save or Save changes button located at the bottom of the page).
