You can't get any further? Then start here and find out how to install and configure Helpful.
Here you will learn how to create your own themes for Helpful, or how to create own fields.
Here you can find the available REST API endpoints and related usage examples.
With filters you can overwrite existing content, or extend it if the source contains an array.
Run your own code with actions whenever Helpful does something for you.
The functions are useful if you want to integrate Helpful deeper into your WordPress website.
Post your question in the forum so I can answer it for you and also others who have the same problem.