You will have to use other apps to create and export files to the icloud Drive. I use my PDF and Open Office app. This is a very time consuming process considering that Documents used to do all this seamlessly. When I bought the app early last October, it worked for less than a month and then crashed. It took three weeks to sort it with their technical team. This was due a faulty update.
Then Beta version that was launched this year was incompatible with the previous version. My files all got saved in the wrong place. I had to create new folders to make them save in the correct locations. Now we are back to the same old problem from last year.
I bought this app on the strength of the rave reviews it got but repeated technical problems, two of which are serious, are denting my confidence in the app.
I have contacted the technical team to complain and hope to get this solved. In my view I don't think they are bug checking their updates properly before releasing them. Perhaps some bad reviews will sharpen up their efforts!