You can enhance the appearance and functionality of the navbar in the UI builder by adding more CSS or HTML content using custom CSS and custom JavaScript under UI builder settings. This approach allows you to insert additional text, buttons, or other elements.
First, use the browser's inspect element feature to identify the ID or class of the navbar component you wish to customize. Once you have located the specific ID or class, you can write custom jQuery to modify it according to your requirements. This method enables you to add additional text, buttons, or other elements dynamically.


Change User Locale In Userview Header – Another example
However, if you're looking to change the entire structure of the navbar fundamentally, you might need to explore building UI theme plugins. How to develop a Userview Theme Plugin