Uploading a caption file for your videos will ensure that all audio is transcribed correctly. Automatic captions can be helpful, but some audio will be undetectable or incorrectly translated. Sometimes the mistakes are neutral or funny, but sometimes they're offensive. The best way to ensure quality captioning is to create the caption file yourself.
Caption files are a specific file type called SRT. SRT stands for Secure Reliable Transport. In addition to writing out all the spoken words and acted content (these are called audio descriptions), each section of captioned text is related to a time window. At that time in your video, the text associated will appear on the screen.
Here's an example of what text in a caption file looks like: