Resources for the InterSystems IRIS Development Professional certification exam

Hi everyone,
I'm getting prepared to take the following certification exam: "InterSystems IRIS Development Professional".

Can you give some advice on how to prepare (aside from the official course page: https://www.intersystems.com/certifications/intersystems-iris-development-professional/ )?
Do you have examples of quiz questions that simulate the real exam or any material that helped you getting prepared?

Thanks you in advance,

Arber