When and where to use Typescript in a React project?

Hello everyone, I've recently started learning typescript after building a couple applications using React. I'm mostly learning via a tutorial video from Dave Gray. It seems like typescript is commonly used with state, component props, and maybe objects created from fetch calls? My question is: What are some common use cases for typescript in React? Should everything be typed all the time? When do you find TS most useful when building React applications? I just want to get a clearer picture of how TS is used and where it is most useful. Thanks all!