Take 2018 finance year for instance:
Go to Ignitia reporting page > download media WIP report (please note that do not select "hide balanced WIP items").
You will see data like below:
Then go to Spectra PF > General Ledger > General Ledger 2018 > Get the Trail balance 2018 report
Total 2018 billings amount of Trail balance report will match with Media WIP report which you got before.