What are some real ways to make a little extra money each month

So right now, I’m working on breaking into the career field I want but in the meantime just working a full time job. I was hoping to get more overtime but they’ve basically told me that the factory is slow and not to expect overtime until like September.

I get bombarded with this clickbait things that are like “8 ways to earn extra money this month!” and then it tells you to like play bingo on your phone for money. If those lists were meant to be real instead of ads, what kinds of things would be on them? What can a working person do to say make $500 a month apart from just getting a second job?