I must be missing something very fundamental.
I converted Airtable's sample extension into my own, and it's running beautifully over localhost:9000, displaying as an extension in my sample base, as you can see below. Everything functions when I check "simulate marketplace extension"

But when I try submitting it for review, running "block submit" from the root (same place I run "block run" from) I got this:

What permissions is it talking about?! What is the "requested model"? It's my own Airtable account, own workspace/base etc--and the code runs locally. What am I missing?
Thanks!