Katalon Web App testing

hello Guys,
i ’ m trying but my effort is futile to find out how to make drag and drop code in Katalon,
i have to programmatically transfer files from desktop to web app,

moreover i am unable to pull out names of my files from my location

thanks in advance for suggestions,
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‘SourcePath’

String strPath = 'C:\\Users\\Desktop\\Files\'

File dir = new File(strPath)

File dir_contents = dir.listFiles()

‘loop for number of files available in the folder to verify file name in the folder’

for (int i = 0; i < dir_contents.length; i++)

{

println ('File Name at'+ i +'is : ' + dir_contents\[i\].getName())  

- no idea why it doesnt work

}