how do I get the insertId for my test to work

I'm doing a backend application without frameworks or ORM for study, and I'm using the mysql2 package for Node and when I'm going to add a book to the table, I can't because the error column author_id cannot be null despite it being filled. Researching I understood that I need to get the insertion id of author and for bookDAO but I couldn't do it. can you help me?

AnthorDAO

import Author from "../models/Author.js"

export default class AuthorDAO {
  constructor(conn) {
    this._conn = conn
  }

  async add(author) {
    if (!(author instanceof Author)) {
      throw new Error(`The object is not an author type`)
    }
    try {
      const authors = await this._conn.query(`SELECT * FROM author`)

      if (authors.some(a => a.email === author.email)) {
        throw new Error(`The author already exists`)
      }
      await this._conn.query(`INSERT INTO author (name, email) VALUES (?, ?)`, [author.name, author.email])
    } catch (error) {
      throw new Error(error)
    }
  }

class Author

export default class Author {
  constructor(name, email) {
    this.name = name
    this.email = email
    this.date = new Date()
  }


  set name(name) {
    if (isEmpty(name) || isNull(name)) throw new Error(`The name field needs to be filled`)
    this._name = name
  }

  set email(email) {
    if (isEmpty(email) || !email.match(emailFormat))
      throw new Error(`The email field must be filled in with a valid format`)
    this._email = email
  }

  get name() {
    return this._name
  }
  get email() {
    return this._email
  }
}

bookDAO

import Book from "../models/Book.js"

export default class BookDAO {
  constructor(conn) {
    this._conn = conn
  }

 async add(book) {
    if (!(book instanceof Book)) {
      throw new Error(`The Object is not of the Book type`)
    }
    try {
      const books = await this._conn.query(`SELECT * FROM book`)

      if(books.some(b => b.title === book.title)){
        throw new Error(`There is already a book registration with that title!`)
      }
      await this._conn.query(`INSERT INTO book (
        author_id, category_id, title, resume, summary, number_of_pages,
        isbn, edition, price) VALUES 
        (?, ?, ?, ?, ?, ?, ?, ?, ?)`, [book.author.id, book.category.id, book.title, book.title, book.summary, book.number_of_pages,
          book.isbn, book.edition, book.price])
    } catch(error){
      throw new Error(error)
    }
}

test with jest

 it("Successfully adding a book", async () => {
    const categoryDAO = new CategoryDAO(conn)
    const authorDAO = new AuthorDAO(conn)
    const bookDAO = new BookDAO(conn)
    const author = new Author("Ana", "Ana@gmail.com")
    const category = new Category("Design")
    await categoryDAO.add(category)
    await authorDAO.add(author)
    const book = new Book(
      author,
      category,
      "Design UX/UI",
      "This book is about Design",
      "Summary",
      40,
      "978-85-13196-08-9",
      50,
      "12"
    )
    await bookDAO.add(book)
    expect(book).toBeDefined()
  })

tables

const table_author = `CREATE TABLE IF NOT EXISTS author(
                id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,
                name VARCHAR(50) NOT NULL,
                email VARCHAR(50) NOT NULL UNIQUE KEY,
                date TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
              )`

const table_book = `CREATE TABLE IF NOT EXISTS book (
                id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,
                title VARCHAR(50) NOT NULL UNIQUE KEY,
                resume VARCHAR(500) NOT NULL,
                summary VARCHAR(500) NOT NULL,
                number_of_pages INTEGER UNSIGNED NOT NULL,
                isbn VARCHAR(17) NOT NULL UNIQUE KEY,
                author_id INTEGER NOT NULL,
                category_id INTEGER NOT NULL,
                edition INTEGER UNSIGNED NOT NULL,
                price FLOAT UNSIGNED NOT NULL,
                time_registration TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
                FOREIGN KEY (author_id) REFERENCES author(id),
                FOREIGN KEY (category_id) REFERENCES category(id)
                ON DELETE CASCADE
              )`

log

   Error: Column 'author_id' cannot be null

      24 |           book.isbn, book.edition, book.price])
      25 |     } catch(error){