Test the app in development mode:
yarn start
Build the app :
yarn build
After building the app there are several ways to serve it. For example:
npx serve build
In the assignment you said to show a trailer if one exists instead of the cover image in detailed view. I checked over a hundred movies and shows, none of which had a video. I didn't put it in because I had no way of testing it. Implementing it would be fairly simple though using conditional rendering.