We know Gutenberg is the name of WordPress‘ new editor, that will change the way you create content in WordPress. This new Gutenberg will have a drastic impact on the existing plugins that used to work on previous editor.
Developers and user shared their concerns about the way this would impact existing websites. Developers has to find new ways of doing things in this new editor.
Riad Benguella created a plugin called Gutenberg Custom Fields, which offers the exact same experience that Advanced Custom Fields has offered in old editor, using Gutenberg Native APIs.