Agurato

<span class="expand">
    <span class="expand-label" style="cursor: pointer;" onclick="$h = $(this);$h.next('div').slideToggle(100,function () {$h.children('i').attr('class',function () {return $h.next('div').is(':visible') ? '{{.Get 2 | default `fas fa-chevron-down`}}' : 'fas fa-{{.Get 1 | default `fas fa-chevron-right`}}';});});">
        {{.Get 0}}
        <i class="{{.Get 1 | default `fas fa-chevron-right`}}"></i>
    </span>
    <div class="expand-content" style="display: none; margin: 10px 0px 10px">
        {{.Inner | safeHTML}}
    </div>
</span>

Agurato

<i class="{{.Get 0}}"></i>