Yes, if you're using the Step-by-step booking form, you can hide any fields when placing the booking form on a page. Clicking the 'Add Bookly booking form' button will open a window with a checklist containing all available fields. Simply ensure that, for the fields you remove, you choose the default value in the same window to ensure proper functionality of the plugin.
Classic editor:
Gutenberg editor:
If you're using one of the modern Bookly forms (Search, Services, or Staff form), navigate to the Appearance section. Open the form and click on the field you wish to hide. Choose a default value and uncheck the 'Show' tick.