I have a form on my page, submitted through Web3forms.com code. How do I make a popup after submission saying “Successful, Thank You” instead of redirecting to another html page for the Thank you message?

<form action="https://api.web3forms.com/submit" method="POST">
          <input type="hidden" name="access_key"value="xxxxxxxxxxxxxxxxxx" />
          <input type="hidden" name="redirect" value="https://mywebsite.com/thankyou.html" />
         <input type="text" name="name" required>
         <input type="email" name="email" required>
                <textarea name="message" required></textarea>
              <input type="checkbox" name="botcheck" class="hidden" style="display: none;">
              <button type="submit">Submit</button>
        </form>