Submitting an extension for review via "block submit" gives Invalid Permissions error

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!