Add Crushed oyster shells with it or any form of calcium carbonate.

I suggest you let it rot in a container in a far corner of the back yard (because of fruit flies etc.) and add anything containing calcium in the process. Maybe some shredded paper to absorb accumulated liquid? I read re. somebody adding broken down oranges/citrus to the worm bin and it seemed fine.

I did that for a while but maybe it wasn't broken down enough. The worms and the entire bin didn't do too well so I stopped. Maybe still too acidic but I saw powdered eggshells and thought it made it neutral enough. The material in the bin became like a paste and I'm sure I added lots of shredded newspaper in the process. And the worms were smaller compared to the other bins. It could be other factors too, who knows, since I don't keep records like in a lab.

Also, newsprint paper nowadays (and CB material) are getting better and better which is bad for composting because they take much longer to break down and are less absorbent.