The previous solution also works well, but this is also interesting. Go to the files app and than to the FiLMic Pro folder. Hold the file and select copy. Open the files app on the iPad and paste it to any location available there, even an external SSD or USB drive. A “Paste from iPhone from [name]” window will appear. This works even if you are not connected to an access point.
is the solution that I was looking for! It may not work for. Large files, or a sequence of several files, but I can live with this. It’s certainly much easier than moving the files via thumb drive. Thank you so much!