delete rtf files in ios 15 files app

As a test I copied (from Mac) an .rtf file into the Pages folder of the files app on an iPhone 12 running ios 15. The test was logging on to the Mac as a server from the iPhone, sharing a read only folder on the Mac. Now, I cannot get rid of this test file on the iPhone. A long press does not show a delete or move option, but does show all the other usual options.. Neither does using select. I tried rebooting the iPhone with no joy. I am not using any iCloud, so I figure this file is locally stored. Other page files and folders in the same Pages folder show the delete and move option, so I figure it has something to do with the filetype being .rtf and being in a pages folder. Pages CAN open and read the file.

How can I delete this file?