If apps let you choose from the iOS Files app and you have FileBrowser installed, you gain access to all your FileBrowser connections such as Windows, Macs, NAS drives or even cloud storage that you setup previously in FileBrowser.
If you need to edit text files or code then Kodex works great too.
Each app is different but it's generally tap "Open" and on the bottom of the dialog tap "Browse". Then tap "FileBrowser" and "Network Folders" and you now have access to all your computers and cloud storage previously set up in FileBrowser.
If you can't see FileBrowser in the list , tap "Edit" above the locations list and switch on the toggle for FileBrowser.
Note: FileBrowser will need to be running in the background.
If you go offline while editing a document, FileBrowser will store your updated files in a folder called 'Pending Uploads'. Your documents are always safe.
When you're back online, open up FileBrowser and tap the 'Pending Uploads' folder. Tap a file to upload the changes back to the server or cloud storage.
You can also save a copy of an edited file to a new location if the original one is unavailable.