how to add a single button with bootstrap code example

Example 1: how to add a button bootstrap

<button class="btn btn-primary">Primary</button>
<a href="#" class="btn btn-secondary">Secondary</button>

Example 2: bootstrap put button on one line

<div class="container">
  <div class="row">
    <div class="col-12 col-md-6">
       <form>
        <button class="btn btn-primary btn-lg" type="submit" formaction="1klasse.html">1.klasse </button>
       </form>
    </div>
    <div class="col-12 col-md-6">
      <form>
        <button class="btn btn-primary btn-lg" type="submit" formaction="1klasse.html">1.klasse </button>
       </form>
    </div>
  </div>
</div>