bootstrap doc buttons code example
Example 1: bootstrap button outline
<button type="button" class="btn btn-outline-primary" href="#">Primary</button>
Example 2: bootstrap buttons
<button type="button" class="btn btn-primary">Blue</button>
<button type="button" class="btn btn-secondary">Grey</button>
<button type="button" class="btn btn-success">Green</button>
<button type="button" class="btn btn-danger">Red</button>
<button type="button" class="btn btn-warning">Orange</button>
<button type="button" class="btn btn-info">Navy Blue</button>
<button type="button" class="btn btn-light">Light Grey</button>
<button type="button" class="btn btn-dark">Black</button>
<button type="button" class="btn btn-link">Link</button>