How to make it work? help

[krvam]

Hello, I need in this code to add the google search engine and that it looks good since I try and I get poorly
I want to like the w3school homepage here: http://prntscr.com/f4773s

This is my site: https://seabu.co

 

This the code of boostrap: 

<div class="jumbotron text-center">
  <h1>SEABUCO</h1> 
  <p>Nos especializamos en ayudar!</p> 
    
<form>
    <div class="input-group">
      <input type="search" class="form-control" size="50" placeholder="Ingresa lo que quieres buscar" required>
      <div class="input-group-btn">
        <button type="submitt" class="btn btn-danger">Buscar</button>
      </div>
    </div>
  </form>

</div>

And this is the code that I have to add in the part where it is to subscribe to the mail replace it by the search engine:

 

<script>
  (function() {
    var cx = '015458911431569616865:0mabwtgo3d0';
    var gcse = document.createElement('script');
    gcse.type = 'text/javascript';
    gcse.async = true;
    gcse.src = 'https://cse.google.com/cse.js?cx=' + cx;
    var s = document.getElementsByTagName('script')[0];
    s.parentNode.insertBefore(gcse, s);
  })();
</script>
<gcse:search></gcse:search>