I just updated my react project dependencies to the latest versions. I updated the "typescript" to "^4.2.2". After that I got this error:

```
src/serviceWorker.ts
    Line 24:16:  'registration' is defined but never used  no-unused-vars

```

Above line is part of the default code by create-react-app "serviceWorker.ts"

```
onSuccess?: (registration: ServiceWorkerRegistration) => void;

```

I tried searching for answers and tried putting this in package.json but I still get the error:

```
"eslintConfig": {
    "extends": "react-app",
    "rules": {
      "no-unused-vars": "off"
    }
  },

```