Could not find react-redux context value; please ensure the component is wrapped in a <Provider> even if already wrapped in a provider

App must be wrapped in provider since you are using useDispatch in it. Right now it's just a child. Provider sets the context so only its children can have access to it, not a parent.

Try:

import { StrictMode, useEffect } from 'react'
import { Provider } from 'react-redux';
import { useDispatch } from 'react-redux';
import { getCurrentUser } from 'store/slices/authSlice';
import store from 'store';
import routes from 'routes/routes';
import PrivateRoute from 'routes/PrivateRoutes';

const AppWrapper = () => {
  const store = createStore(rootReducer);

  return (
    <Provider store={store}> // Set context
      <App /> // Now App has access to context
    </Provider>
  )
}

const App = () => {
  const dispatch = useDispatch();

  useEffect(() => {
    firebase.auth().onAuthStateChanged((user) => {
      if (user) {
        // User is signed in, see docs for a list of available properties
        // https://firebase.google.com/docs/reference/js/firebase.User
        var uid = user;
        console.log(uid);
        dispatch(getCurrentUser(uid))

      } else {
        // User is signed out
        // ...
      }
    });
  }, [dispatch]);

  return (
    <StrictMode>
      <Provider store={store}>
         <Router>
            <Switch>
              {routes.map((route, i) => (
                route.auth ? (
                  <PrivateRoute
                    key={i}
                    exact
                    path={route.path}
                    component={route.component}
                  />
                ) : (
                  <Route
                    key={i}
                    exact
                    path={route.path}
                    component={route.component}
                  />
                )
              ))}
            </Switch>
          </Router>
      </Provider>
    </StrictMode>
  );
}

export default App;

The problem is that you are trying to use useDispatch in your main component, which is not wrapped with a Provider. You should create a navigator or router component and do it inside that one