Custom Text Link in navigation

I want to add Custom Text Link in main Navigation.
Although i got the code
<a href="#" id="livilyChatLink" class="livilyChatButton ClickdeskChatLink" image="false" onclick="return false;">ClickDesk Live-Chat</a>
But how can i add this code in main Navigation.

https://ww.wp.xz.cn/plugins/clickdesk-live-support-chat-plugin/