Are you asking about the user details on the checkout process?

On the “Your Shopping Cart” page in the “Billing information” box I want to be able to edit these fields.

although you might be able to change the label on these fields using the Localization app, I don’t think there is any way to change the fields. the checkout page almost feels like a separate app and not a native Docebo app (am guessing). You can always ask support if they know whether these can be changed.