Ethiopia has one of the lowest smoking rates in the world. How? It's banned in public places, it cannot be flavoured, warning labels must be included, and there are high taxes.
How do we do the same for Twitter? We ban the app from being downloaded from the apple/play store (downloading an apk is fine). We prohibit Twitter from showing ads to users in the country. We require a warning on each page load that Twitter promotes Nazi content, and we tax Twitter just to do business in the country.
If Twitter doesn't agree to those terms, they can stop doing business in this country. They still have the option of getting revenue from blue checkmarks, so it's not like it's impossible for them to operate. They just have to follow certain restrictions on how they conduct business, just like Cigarette companies have to.