Landing Page constructors for admin panel?

Question

Landing pages

Are there any ready-made library solutions, in particular for Symfony, that can be used to visually create/change Landing Page pages, in particular forms, buttons, etc., with the ability to add your own elements, such as on the site builder Wix?

Answer 1

the library does not care what to design - admin panel or non-admin panel,
take the wix library and do