iOS office app with nextcloud access

I‘m searching for any iOS app for editing MS Office and OpenDocument Files which are able to load/save from/to my Nextcloud server.

I‘m aware of that feature in the paid version of MS Office 365 apps, however the way to load and save docs in MS Word on Nextcloud is rediculous cumbersome. So this is just no solution.

I‘m also aware of Nextcloud Collabora, however that requires to be online. I need a way to load & edit a doc that is stored on my device in the Nextcloud App even when I‘m offline.

Any recommendations?

I search for the same