[Help Wanted] Problem importing Plaintext->Simplenotes

[jockm]

I am trying to get my notes from Notion into Simplenotes. I exported from Notion, ran the Notion to Obsidian script — which just removes the embedded UUIDs and leaves a clean directory structure of markdown files and attachments

I then went to standard notes tools and uploaded the zip file of my converted notes, this produced a sn-import-file.txt

Then according to this page I then did a Import From Backup...

...but the result was that I have a single note which is just the contents of the sn-import-file.txt file.

What am I doing wrong, and how could I have found the right answer on my own?