I’ve found this to be the most frustrating of all my Pico add-on boards. Lack of clear documentation about the correct pins is not helping. It has been out long enough for this to have been sorted by now. The ‘home-made’ SDcard adapter method works perfectly in MicroPython - build your own.
All we need is a simple example program, in MicroPython, which initialises the board, opens a write-file, writes a couple of records, closes the file, opens it for reading and gets the stored information back.