Sometimes an app works with QBO, and then it doesn't.
If it is a problem with the Intuit Platform, you can check the status of all Intuit Platforms at https://intuitdevelopergroup.statuspage.io/
If you do not see any issues listed at the website above you can request the Admin user go to the Apps section of QuickBooks Online and disconnect the App and then reconnect the App.
If this does not resolve the issue reach out to the App developer directly.
(Taken from Transaction Pro Importer support article)