How to set an button align-right with Bootstrap?

Bootstrap 5 implementation:

The class name is now “float-end” instead of “pull-right”

<div class="alert alert-info clearfix">
    <a href="#" class="alert-link">
      Summary:Its some description.......testtesttest
    </a> 
    <button type="button" class="btn btn-primary btn-lg float-end">
      Large button
    </button>
</div>

Bootstrap 4 (and under) implementation:

Just add a simple pull-right class to the button, and make sure the container div is clearfixed:

<div class="alert alert-info clearfix">
    <a href="#" class="alert-link">
      Summary:Its some description.......testtesttest
    </a> 
    <button type="button" class="btn btn-primary btn-lg pull-right">
      Large button
    </button>
</div>