step 40 please help

Tell us what’s happening:
Describe your issue in detail here.

  **Your code so far**
<html>
<body>
  <h1>CatPhotoApp</h1>
  <main>
    <section>
      <h2>Cat Photos</h2>
      <!-- TODO: Add link to cat photos -->
      <p>Click here to view more <a target="_blank" href="https://freecatphotoapp.com">cat photos</a>.</p>
      <a href="https://freecatphotoapp.com"><img src="https://cdn.freecodecamp.org/curriculum/cat-photo-app/relaxing-cat.jpg" alt="A cute orange cat lying on its back."></a>
    </section>
    <section>
      <h2>Cat Lists</h2>
      <h3>Things cats love:</h3>
      <ul>
        <li>cat nip</li>
        <li>laser pointers</li>
        <li>lasagna</li>
      </ul>
      <figure>
        <img src="https://cdn.freecodecamp.org/curriculum/cat-photo-app/lasagna.jpg" alt="A slice of lasagna on a plate.">
        <figcaption>Cats <em>love</em> lasagna.</figcaption>  
      </figure>
      <h3>Top 3 things cats hate:</h3>
      <ol>
        <li>flea treatment</li>
        <li>thunder</li>
        <li>other cats</li>
      </ol>
      <figure>
        <img src="https://cdn.freecodecamp.org/curriculum/cat-photo-app/cats.jpg" alt="Five cats looking around a field.">
        <figcaption>Cats <strong>hate</strong> other cats.</figcaption>  
      </figure>
    </section>
    <section>
      <h2>Cat Form</h2>
      <form action="https://freecatphotoapp.com/submit-cat-photo">
        <input type="text" name="catphotourl" placeholder="cat photo URL""bell">
      </form>
    </section>
  </main>
</body>
</html>
  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36

Challenge: Step 40

Link to the challenge:

Add an empty attribute value “required” which makes this field compulsory for the viewers to input in

First, there is no “bell” in the line above.
You just need to add required="" to the input line above.