did not notice that Service work, is used in create-react-app to modify the code after it is launched, and the browser cannot be updated. How to make html update forcefully.

before index.js did not add hash, now index on the server all add hash. Some browsers still visit without hash code before, which means that the browser did not send a request to the server. If you don"t request the server, is it just like the new service wrok,? I don"t quite understand. Please give me some advice