How to upload pdf file to div tag name

tried the following & get error :
FileLocation = CustomKeywords.‘sample.Login.PathFile’(’\Data Files\CreditReport_20210429.pdf’)

WebUI.uploadFile(findTestObject(‘Pages/Purchasing/MilestoneThree-GetApproved/DocumentUpload/UploadFile’), FileLocation)


custom keyword :
@Keyword
public static String PathFile(a) {
String userDir = System.getProperty(‘user.dir’)
String filePath = userDir + a
return filePath
}

the error :
org.openqa.selenium.ElementNotInteractableException: element not interactable
At object: ‘Object Repository/Pages/Purchasing/MilestoneThree-GetApproved/DocumentUpload/UploadFile’

com.kms.katalon.core.exception.StepFailedException: Unable to upload file ‘C:\Users\nkhouri\Documents\Simplist\Data Files\CreditReport_20210429.pdf’ to object ‘Object Repository/Pages/Purchasing/MilestoneThree-GetApproved/DocumentUpload/UploadFile’

Worked using the following :
on custom key:

@Keyword
//### get file path according to the project location
public static String PathFile(a) {
	String userDir = System.getProperty('user.dir')
	String filePath = userDir + a
	return filePath
}
@Keyword
//### upload file from windows explorer
def uploadFile (TestObject to, String filePath) {
	WebUI.click(to)
	StringSelection ss = new StringSelection(filePath);

	Toolkit.getDefaultToolkit().getSystemClipboard().setContents(ss, null);

	Robot robot = new Robot();
	robot.delay(1000)
	Thread.sleep(3000)
	robot.keyPress(KeyEvent.VK_ENTER);
	robot.keyRelease(KeyEvent.VK_ENTER);
	robot.autoDelay;
	robot.keyPress(KeyEvent.VK_CONTROL);
	robot.keyPress(KeyEvent.VK_V);
	robot.keyRelease(KeyEvent.VK_V);
	robot.keyRelease(KeyEvent.VK_CONTROL);
	robot.autoDelay;
	robot.keyPress(KeyEvent.VK_ENTER);
	robot.keyRelease(KeyEvent.VK_ENTER);
} 

on test case :
WebUI.click(findTestObject(‘Object Repository/Pages/Purchasing/MilestoneThree-GetApproved/Sections/documentUpload’))

FileLocation = CustomKeywords.‘sample.Login.PathFile’(’\files\CreditReport_20210429.pdf’)

CustomKeywords.‘sample.Login.uploadFile’(findTestObject(‘Pages/Purchasing/MilestoneThree-GetApproved/DocumentUpload/UploadFile’),
FileLocation)

WebUI.verifyElementVisible(findTestObject(‘Pages/Purchasing/MilestoneThree-GetApproved/DocumentUpload/uploadedByME’))

WebUI.click(findTestObject(‘Pages/Purchasing/MilestoneThree-GetApproved/DocumentUpload/backToDashboard’))