Configurable List widget: Required field function not working after adding CSS codes to make it responsive

It's become responsive. But the "*" to require the filed function is not working by then. How to fix it?

When you injected the custom CSS codes into the Configurable List widget in your form, the "*" that indicates the field is required is removed because it is part of the field label that was hidden by the CSS codes. However, the form will work the same without the asterisk.

With asterisk:

Without asterisk (CSS codes injected):

Feel free to let us know if you need any further assistance.