@DeepDiver1975 Exactly this is not the case here. The app can't be enabled from within ownCloud as you're getting an "Signature could not get checked. Please contact the app developer and check your admin screen." message and the yellow integrity banner when doing so.
This is also e.g. reported at the appstore, as well as on e.g. [1]. However the app developer denies to fix this signature issue [2].