This product contains a code plugin, complete with pre-built binaries and all its source code that integrates with Unreal Engine, which can be installed to an engine version of your choice then enabled on a per-project basis.
Register "MyEvent" in a UMG widget then call "MyEvent" from ANYWHERE in your project, for example in the Game Mode, Game Instance or your Level Blueprint, without having to reference the UMG widget, you can call the "MyEvent" and it will be executed inside your UMG widget.