How to make money in spare time?

How do I make extra money in my downtime?

I am fortunate to work a job that I enjoy and make a decent wage. I work remote and have a lot of downtime, unfortunately overtime is not an option. I’m not looking for a second job as I don’t want to risk the one I have now. I’m really just looking to make some extra money in my downtime. Is there any way to make guaranteed profit/money with little effort? I’m not looking to make crazy money or a get rich quick scheme or a course. Just something I can do (either digitally or physically) to make a little extra cash. Give me your ideas!