Bithumb Singapore has two (2) steps of the authentication system.
Signing up with Bithumb Singapore gives you the level 1 position by default. You can now upgrade your level by submitting all required information and documents.
One of the provided benefits from Bithumb Singapore for a level 2 user is that the withdrawal limit is expanded from 0.3 BTC to 20 BTC. The other one is that you will be able to participate in almost all events.
If you wanted to be the level 2 user, please move on to the Profile Management page and then submit all required information with documents. It might take lots of time for you to be verified please understand.
Please refer to the below link for detailed information.