The reason I'm asking is that I want to practice typing in Chinese on TypeRacer, but it's currently very inconvenient to use. If the word I'm trying to type is "你好", it warns me that I've made a typo as soon I type "n", because it doesn't match "你". How do I make it so that only Chinese characters are outputted as I am typing?
That is the problem of TyperRacer, not the IME or you. I suggest you using platforms created by Chinese speaking people, which could be optimized for Chinese practice.
For example https://dazi.kukuw.com/keyboard.html