I use heights course platform and go4click.

The problem is that the quiz has to live on the internet so if I just provide a link then anyone can take my link and use my course content.

As they would be my students I don’t need to lead gen them. And for a leaderboard there’s no way to bring that data back into the course platform.

Is there any creative solution you have for password protecting my quiz or integrating with these two platforms?

I see a huge potential in gamifying learning.

https://interacty.me/products/memory-games-for-teachers

Here you only had one example for teachers but still good one for tests and quizzes.