Mobile apps don't recognize my username and pawword for FileRun

I have installed FileRun system on my payd hosting. On my smartphone I install FileRun app, but they have a problem with mobile version. They advised me to use Nextcloud mobile app with my FileRun name and pass. But Nextcloud app don’t recognize my name and pass. Then I write my server address and name and pass I can’t login.
Any idea why ?

PS: Link to FileRun Communitie -->