Not sure if I understand your question. You ask how to add required jar
file to a Netbeans project. Then you say that it works fine when you
test it under Netbeans. I take it you do not want to update your HTML to
make it run.

If so, under your Netbeans project just this It is a two step process.
One add library to Netbeans and then add that library to your project

External jar file just for project
1 - select your project, right click and select properties
2 - select libraries
3 - select Add jar\folder. Then add it and select OK

External jar file as a library that any project can us. After this is
done Netbeans will let you add the library to any project with out
having to make a reference for it's location

1 - select your project, right click and select properties
2 - select libraries
3 - select add new library and then Manage Libraries
4 - enter a symbolic name for the library
5 - your new library reference now hows in the library list
6 - select that library
7 - select Add jar\folder. Then add it and select OK
8 - The finally select OK.
9 - The external jar file is associated with a Netbeans library name. So
on any project you can just add this library.