The best side hustle right now would be to sell an online course or an ebook. This is not going to be very easy though.
You need to first build your user base. You need to have a user base to sell something to. There is a few ways to do this:
Youtube channel Twitter Github
Once you have a follower base belonging to a particular niche, its easier to sell to them than to random paid followers you can get on fb.
Plenty of programmers and designers do this. This takes time, you need to post quality content to build up a user base and then sell them something they need.