I have a need that I can make a hidden button and then fire a click event script on it programatically in my PDF.
Also the scripts I define in PDf advanced document processing document level script section how can i call them via itext let's say or use that script to fire as click event on button.
You can't simulate a click event using JS. But what is the need for that? If the button just executes a script, then simply run that script.
If you write them as a function, you can call that function anywhere in the PDF document or by use of a plugin or external application through the Acrobat API.