Thanks for your interest in translating for Gengo.
Tests from English to Chinese and viceversa are currently closed. (Read more about this here: https://support.gengo.com/hc/en-us/articles/231441627-I-can-t-find-the-test-for-my-language-pair).
We open and close tests based on availability and customer demand, so it is possible that we will open them again in the future, though there is no way of telling when this would happen. If you are interested, you can leave your name and email address here (http://svy.mk/1SBA6Rf) to receive a notification if / when the tests are open again.
Hope this helps, and let me know if you have any further questions.