Live Demo: Bootstrap 4 Buttons with Icons

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Bootstrap 4 Buttons with Icons</title>

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@4.6.0/dist/css/bootstrap.min.css">

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.5.0/font/bootstrap-icons.css">
<style>
    .bs-example{
        margin: 20px;        
    }
</style>
</head>
<body>
<div class="bs-example">
    <button type="submit" class="btn btn-primary"><span class="bi-search"></span> Search</button>
    <button type="submit" class="btn btn-secondary"><span class="bi-search"></span> Search</button>

<script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/bootstrap@4.6.0/dist/js/bootstrap.bundle.min.js"></script>
</div>
</body>
</html>