Как активировать галерею от отдельной кнопки, а не кликом на картинку?

$('.materialboxed').materialbox();

.btn {
    position: absolute;
    top: 10%;
    background: #fff;
    left: 10%;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/css/materialize.min.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/js/materialize.min.js"></script>

<img class="materialboxed" width="650" src="https://materializecss.com/images/sample-1.jpg">
<a href="#" class="btn">увеличить</a>