Settings are located at Edit / Project Settings… / New UI Widgets.
Enable/disable assembly definitions. Enabled by default.In the case of supported third-party packages without assembly definitions you need to create assembly definitions and specify them as references in the
Create widgets as copies of prefabs (same as default Unity widgets) or as prefabs references. Create copies by default.
Styles or Themes
Enable/disable TextMeshPro Support. Enabled by default if the TextMeshPro is installed.
Data Bind for Unity Support
Enable/disable Data Bind for Unity Support.
I2 Localization Support
Enable/disable I2 Localization Support.
UI Themes Wrappers Settings
Specify folder, and namespace for wrappers, and enable generate wrappers for UI Themes.
Support is enabled only to installed platforms. Platforms that were added after it requires enabling support again.