How to get iPhone to load files from dropbox

I cannot upload files from my iPhone to my woodworker. Has anyone found a way to make this work?

I tried the suggestion in this thread by changing the .nc to .txt. I still cannot upload a file to my woodworker this way.

Changing the extension did change the file browser icon from a ? to a text looking document, but it still cannot be opened/uploaded to the machine. I copied from dropbox to have it local on the phone. I tried saving at a Pages document. None of this has enabled me to use my phone to load a file to the machine. Shuttling thumb drives from my computer to the shop is what I’ve been doing. Its gone from inconvenient to annoying.