By default only way to expose panel is to click on button with Font Awesome icon. But you can control this. Just add class nks_cc_trigger_element to any element on page (link, button, image) in your WP HTML editor. And click on this element will show panel.

<a href="#" class="nks_cc_trigger_element">Press me</a>

By default it opens first tab this way. If you want to open specific tab add also class nks_toggle_tab_* where asterisk is tab number.

<a href="#" class="nks_cc_trigger_element nks_toggle_tab_2">Press me to open tab #2</a>

Or use API method NinjaSidebarCustom.showSidebar() in your code to show panel programmatically. Also you have option to hide icon label.

And finally you can add class from plugin main script. Let’s for example make all links to open the panel. Add this snippet at the very beginning of ninja-contact-form.min.js:

jQuery(function($) { // on DOM ready

Especially it’s useful for adding class to menu item because it’s usually difficult to control menu HTML.

Tip: in WordPress on Appearance/Menus page click Screen Options in upper right corner. Then choose CSS classes in Show advanced menu properties.