If you're interested in gaining access to the 성인 titles available on Ridibooks then you'll have to send a picture to the team so that they can verify your age. It took me a while to figure out how to do this as the method is different for foreign nationals.
The method for Koreans involves downloading programmes and apps to verify your identity but the version for foreigners is much more simple and more akin to something like Amazon. There is a simple link you can click to take you to the page where you fill out your details here.
You can watch the video below or continue reading for some basic troubleshooting:
