Can you offer freelance services, programming, consulting?
Could you build an audience/sell info products/courses to teach something you understand very well.
Could you share information in a blog to get enough traffic for ads/affiliate sales.
Could you teach an online course related to your profession or write online course for a certification exam you have passed.
Think about what skills, knowledge you have and what would be valuable to others. Offer free advice, write a blog, start getting more involved in the community where people would find this valuable.
Try different things to find what works for you and what you enjoy doing.