How to drain the sink in Orange Hotel?

There is a metal pull ring next to the faucet on the washbasin. Pull it up and the water will be released.

The water in the hotel washbasin can be pressed by the metal piston at the bottom. There is a metal cylinder at the bottom of the washbasin, which can be turned and leveled. If you want to let the water out of the washbasin, just turn the metal cylinder at the bottom upside down and the water will come out. If you don't want to drain water, put the cylinder flat. The cylinder at the bottom can rotate up and down.