Do you have two files, a ZIPPED ROM in the \Roms folder and an UNZIPPED (Visual Pinball) .vpt table file in the \Tables folder for each VPinMame table?
You need one of each for VPinMame tables.
Visual Pinball-only tables don't need a ROM, though they might have other necessary files in the .zip download that need to be unzipped and put in the correct folders.
You can interact with the ChatGPT Bot in any Chat Room and there is a dedicated room. The command is /ai followed by a space and then your ? or inquiry.
ie: /ai What is a EM Pinball Machine?