AUI - icons not shown in HBS views

Hi everyone,

I am trying to include AUI icons (Icons - AUI Documentation) to my Atlassian connect (express) app but face the problem that the majority of icons are not rendered in my Handbelars views.
It successfully worked with “calendar” but e.g. “person” icon is not shown. I added following html tags to my view:

<span class="aui-icon aui-icon-small aui-iconfont-calendar">creationDate</span>
<span class="atomic-item-text-light">Created at: {{{ convertToSimpleDate creationDate }}}</span>
<span class="aui-icon aui-icon-small aui-iconfont-person">creator</span>
<span class="atomic-item-text-light">Created by: Alpha Kevin</span>

Following will be rendered: