The extended component contains the boiler plate codes, in which you need to make the changes as shown in the below HTML Changes (Extended Component) screen. After you make the necessary changes, the additional fields will be added after the existing fields in the base component.

The following changes are required only if you need to add the additional field at the end of the base component and in a separate extension panel. You can choose to add the additional fields in the existing base component or in the extension panel as per the requirement.