The default shortcode name is ‘click’.
To add the shortcode in posts, pages – Add [click]
To change the shortcode name, use the “shortcode name” field and enter the shortcode name that must be unique, different from other shortcodes, so please add shortcode name that should not conflict with other shortcodes created by themes, other plugins, default WordPress shortcodes.
If the shortcode name is changed to ‘chat’ then add [chat] in posts, pages.
While changing the shortcode name make sure that, the previous shortcode name’s are not used at any place. Shortcode names must be unique with the WordPress Website.