I'll be completely honest with you:
There are sites where you can freelance (Google 'freelancing sites') BUT you're up against about 10,000 other people all wanting to do the same thing and tendering for the same jobs (especially since Covid hit - people are really desperate to work from home). Even more specialised roles get applicants who will put their hand up for everything and it's bloody hard to get your foot in the door. And until you build up a reputation (100% positive feedback) - which can take years to achieve, you'll be working for absolute peanuts (after you've built up a reputation, the clients start coming to you, which makes it worthwhile). When I first started, I spent a whole month of 18-hour days working on something, for which I got paid US$1k, less the freelancing site fee, less the PayPal transfer fee ... I was left with just a few hundred dollars. Alternatively, you could advertise your specialty locally via letterbox drop or similar.
If you don't have a particular skill, your best bet is to find something that nobody likes doing - ironing, cleaning, rubbish removal, decluttering ... but it isn't going to give you a great income (not at first, anyway). If you go down the cleaning route, do private homes rather than commercial premises ... and you might even be able to suggest other ways to help (e.g., meal preparation, shopping, etc.).
I had a friend who did telephone sex work - she has a very sexy voice. But that was in the '90s and I don't even know if it's a thing anymore.
Only Fans isn't worth risking your reputation and self-respect for - besides, most of the content gets uploaded to sites like Reddit for free.
If you're really good at something schoolkids need help with, you could advertise yourself as a private tutor ... my godson has a maths tutor who charges NZ$80/hr ... the tutor is a university student and it's a nice little earner for him.
Steer clear of MLMs!