gatsby-pingbot/src/pages/404.js

import  React from 'react'
import AniLink from 'gatsby-plugin-transition-link/AniLink'

import Seo from '../components/seo'

const NotFoundPage = () => {
  return (
    <>
      <Seo
        title="Not found"
      />

      <h1>Page not found</h1>
      <p>
        Sorry we couldn’t find what you were looking for.
        <br />
        <AniLink cover to="/">
          <button className="blue-button">Go to home page</button>
        </AniLink>
      </p>
    </>
  )
}

export default NotFoundPage