В this.state.allbook хочу добавить объекты у которых key будет те именна которые я получаю из базы. book.key , у меня не получается добавить объекты

import React, { Component } from 'react';
import './SearchBooks.css';
import axios from 'axios';

export default class SearchBooks extends Component {
    constructor(props) {
        super(props)

        this.state = {
            nameBooks: '',
            allBooks: null,
            allBook: {}
        };
        this.timerId = null;
    }

    searchBooks = (e) => {

        this.setState({
            nameBooks: e.target.value
        });

        if (this.timerId) {
            clearTimeout(this.timerId);
            this.timerId = null;
        };

        this.timerId = setTimeout(() => {
            const books = [];
            axios.get(`http://openlibrary.org/search.json?title=${this.state.nameBooks}`)
                .then(res => {
                    const titleBooks = res.data.docs;
                    titleBooks.map(book => {
                        books.push(book.title)
                        book.key = {}
                        this.setState({
                            allBooks: books
                        });
                        console.log(this.state, 'allbook')
                    });
                });
        }, 1000);
    };

    async getBooks() {

    }

    render() {
        return (

            <div className='SearchBooks'>
                <div className='title'>
                    <h1>Look for your favorite book </h1>
                </div>
                <div className='search'>
                    <input onChange={this.searchBooks} className='inp' type='text' />
                </div>
                <i className="fa fa-search " onClick={() => this.getBooks()} />
                <div className='bookBox'>
                    {this.state.allBooks ?
                        this.state.allBooks?.map(book => {
                            return (
                                <span className='book'>{book}</span>
                            )
                        })
                        :
                        null
                    }
                </div>
            </div>
        );
    };
}