Are you a good teacher? Do you have an area of expertise that you teach or help others in already? You could create an online course around that topic and sell it. Sites like Udemy allow anyone to create an online course and then sell it through their platform. There are courses for everything, so don't worry if you think that your topic is too obscure.
What these opportunities typically turn up to be is a pyramid scheme. You pay a fee to signup. You then receive a flyer saying how great stuffing envelopes is and list of names and addresses to mail said flyer. IF those people pay that signup fee so they can mail that flyer too, you get paid a small referral fee. ONLY if they take the bait do you get paid.
How much will you make? I think my best month with Google AdSense was almost $5,000 over the last ten years. That amazing month blew my mind since it was actually near the beginning of my blogging journey. When you go from making zero to $5,000 in a month, that will rock your world. For me, it also got me even more excited because I knew there were other ways to monetize.