This is how it looks like

Store.js
import { applyMiddleware } from 'redux';
import { configureStore } from '@reduxjs/toolkit'
import { composeWithDevTools } from 'redux-devtools-extension';
import thunk from 'redux-thunk';
import rootReducer from './reducers';

const initialState = {};

const middleware = [thunk];

const store = configureStore({
    reducer: {
        authReducer: rootReducer,
        starterState : initialState,
        devTools: composeWithDevTools(applyMiddleware(...middleware)),
    }
});

export default store;

index.js (rootReducer)

import { combineReducers } from 'redux';
import auth from './auth';

export default combineReducers({
    auth
});

auth.js

import {
    LOGIN_SUCCESS,
    LOGIN_FAIL,
    USER_LOADED_SUCCESS,
    USER_LOADED_FAIL,
    AUTHENTICATED_SUCCESS,
    AUTHENTICATED_FAIL,
    PASSWORD_RESET_SUCCESS,
    PASSWORD_RESET_FAIL,
    PASSWORD_RESET_CONFIRM_SUCCESS,
    PASSWORD_RESET_CONFIRM_FAIL,
    SIGNUP_SUCCESS,
    SIGNUP_FAIL,
    ACTIVATION_SUCCESS,
    ACTIVATION_FAIL,
    LOGOUT
} from '../actions/types';

const initialState = {
    access: localStorage.getItem('access'),
    refresh: localStorage.getItem('refresh'),
    isAuthenticated: null,
    user: null
};

export default function (state = initialState, action) {
    const { type, payload } = action;

    switch (type) {
        case AUTHENTICATED_SUCCESS:
            return {
                ...state,
                isAuthenticated: true
            }
        case LOGIN_SUCCESS:
            localStorage.setItem('access', payload.access);
            localStorage.setItem('refresh', payload.refresh);
            return {
                ...state,
                isAuthenticated: true,
                access: payload.access,
                refresh: payload.refresh
            }
        case SIGNUP_SUCCESS:
            return {
                ...state,
                isAuthenticated: false
            }
        case USER_LOADED_SUCCESS:
            return {
                ...state,
                user: payload
            }
        case AUTHENTICATED_FAIL:
            return {
                ...state,
                isAuthenticated: false
            }
        case USER_LOADED_FAIL:
            return {
                ...state,
                user: null
            }
        case LOGIN_FAIL:
        case SIGNUP_FAIL:
        case LOGOUT:
            localStorage.removeItem('access');
            localStorage.removeItem('refresh');
            return {
                ...state,
                access: null,
                refresh: null,
                isAuthenticated: false,
                user: null
            }
        case PASSWORD_RESET_SUCCESS:
        case PASSWORD_RESET_FAIL:
        case PASSWORD_RESET_CONFIRM_SUCCESS:
        case PASSWORD_RESET_CONFIRM_FAIL:
        case ACTIVATION_SUCCESS:
        case ACTIVATION_FAIL:
            return {
                ...state
            }
        default:
            return state
    }
};

Navbar,js

import React, { Fragment, useState } from 'react';
import { Link, Navigate } from 'react-router-dom';
import { connect } from 'react-redux';
import { logout } from '../actions/auth';

const Navbar = ({ logout, isAuthenticated }) => {
    const [redirect, setRedirect] = useState(false);

    const logout_user = () => {
        logout();
        setRedirect(true);
    };

    const guestLinks = () => (
        <Fragment>
            ...
        </Fragment>
    );

    const authLinks = () => (
        ...
    );

    return (
        <Fragment>
            <...
                        {isAuthenticated ? authLinks() : guestLinks()}
...
        </Fragment>
    );
};

const mapStateToProps = state => ({
    isAuthenticated: state.auth.isAuthenticated
});

export default connect(mapStateToProps, { logout })(Navbar);