Reactjs ne peut pas trouver le fichier ServiceWorker.js dans le dossier de l'application SRC
// you have to create a new react app. but this time with an extended code
npx create-react-app my-app --template cra-template-pwa
//this creates a react app plus the serviceWorker.js file in your app
// rem this errors occur bcoz you are using latest dependancies
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