The configuration ui property defines options related to the editor UI, and allows for the configuration of the editor toolbar.

Properties

aria-label
StringText to use for the editor's ARIA label instead of the default
autoresize
BooleanAutomatically scale the vertical height of the editor to fit the content

colors 

ObjectSpecifies the list of colors available to the editor
fonts
ArraySpecifies the list of fonts available to the editor
languages
ArraySpecifies available language codes that can be applied to content for internationalization (HTML lang attribute)
locale
StringSpecifies editor UI language
shortcuts
BooleanWhether to enable content keyboard shortcuts
toolbar
ObjectAn object representing the desired toolbar functionality for an editor.