Difficult to use NZB Usenet Serch

Can’t a simple search bar for .nzb files in Torbox app be added instead. Spent half a day trying to figure out how to search for NZB files. Thought by buying PRO subscription didn’t need to pay for additional indexers, add-ons require payment to use service. Have installed Orion and Stremio but still can’t search for NZBs.