Add text if ParagraphStyle is found

Try the following code

function addTextToPara(pStyleName, prefixText)
{
       app.findGrepPreferences.appliedParagraphStyle = pStyleName
       var paraList = app.activeDocument.findGrep()
       for(var i = 0 ; i < paraList.length; i++)
       {
            paraList.contents = prefixText + paraList.contents
       }
       app.findGrepPreferences = NothingEnum.nothing;
}
//Change the argument with the name of the paragraph style you want to search and the text you want to add before that para
addTextToPara("Paragraph Style 2", "<1>") 

-Manan