Tom,
You can only open a file with the same or later (newer) version. So 2023 R2 or later.
I don’t work at Ansys, but I doubt you will find anyone who would export the neutral file.
Since Rob brought it up, I can walk you though the many steps that should result in being able to export an STL file after you build and mesh a model.
Peter
You are navigating away from the AIS Discovery experience