bigbluebutton-Github/client/bbb-html5-client/public/templates/chat_private_tab.html

<button id="chat-private-btn-<%= userid %>" class="chat-private-btn btn btn-default btn-sm" data-username="<%= username %>" data-userid="<%= userid %>">
  <%= username %>
</button>
	`<button id="chat-private-btn-<%= userid %>" class="chat-private-btn btn btn-default btn-sm" data-username="<%= username %>" data-userid="<%= userid %>">`
	`<%= username %>`
	`</button>`