I have included below
<!-- Bootstrap 4.0 Beta -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-beta/css/bootstrap.min.css" integrity="sha256-m/h/cUDAhf6/iBRixTbuc8+Rg2cIETQtPcH9D3p2Kg0=" crossorigin="anonymous" />
<!-- open-iconic-bootstrap (icon set for bootstrap) -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/open-iconic/1.1.1/font/css/open-iconic-bootstrap.min.css" integrity="sha256-BJ/G+e+y7bQdrYkS2RBTyNfBHpA9IuGaPmf9htub5MQ=" crossorigin="anonymous" />
And used this as below with no luck
<span class="oi oi-icon-person" title="person" aria-hidden="true"></span>
Use oi-person
class instead of oi-icon-person
:
<!-- Bootstrap 4.0 Beta -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-beta/css/bootstrap.min.css" integrity="sha256-m/h/cUDAhf6/iBRixTbuc8+Rg2cIETQtPcH9D3p2Kg0=" crossorigin="anonymous" />
<!-- open-iconic-bootstrap (icon set for bootstrap) -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/open-iconic/1.1.1/font/css/open-iconic-bootstrap.min.css" integrity="sha256-BJ/G+e+y7bQdrYkS2RBTyNfBHpA9IuGaPmf9htub5MQ=" crossorigin="anonymous" />
<span class="oi oi-person" title="person" aria-hidden="true"></span>