Can any Marrow user please explain how to use Custom module to improve performance?

Can any Marrow user please explain how to use Custom module to improve performance? I have never used it before. I’ll be grateful if anyone can please guide.

It’s like a random qbank generator u can use to strengthen ur weak areas. U can select subjects, topics , tags and difficult level and the app randomly generates the number of questions u want which u can answer either in exam mode or regular mode. It’s especially useful for people revising.