If the Import File is showing the "No. of Line Items" as being zero, then:
- Make sure the Import File upload processor has completed. This will often happen pretty much straight away, but may on very rare occasions take upto an hour to process. Wait for the Confirmation email that is sent once the processing has completed before checking.
- Check the Payments2Us Error Log to see if there are any entries/reasons there.
- Make sure your user has a Payments2Us Permission Set assigned to it.
- Navigate to setup > Quick find "Apex Jobs" and click into "Apex Jobs" menu item.
Look for a row that has an Apex Class of "ImportFileProcessor". Check the "Status Details" column to see if there are any error messages there.