How can I run a report with Pending (Incomplete Transaction)?
Pay Later isn't available in reports provided by core civicrm. I added this to extendedreport extension recently - https://github.com/eileenmcnaughton/nz.co.fuzion.extendedreport/pull/434
The PR is merged so you can use the latest (or master) version and use contribution details extended report to find the required filter.