App https://hybrit.org/blog/combine-headless-wordpress-with-a-react-spa-part-1

App.js

import React, { Fragment } from "react";
import axios from "axios";
import "./App.css";

export default class App extends React.Component {
    constructor(props) {
        super(props);

        this.state = {
            pages: []
        };
    }

    getAllPages = async () => {
        let res = await axios.get(
            `http://localhost:8000/?rest_route=/wp/v2/pages`
        );
        let { data } = await res;

        this.setState({ pages: data });
    };

    componentDidMount = async () => {
        await this.getAllPages();
    };

    render() {
        const { pages } = this.state;

        return (
            <Fragment>
                {pages.map((page, index) => {
                    return <h1>{page.slug}</h1>;
                })}
            </Fragment>
        );
    }
}