I've got some Google Sheet script code that I'd like to extract into Google Sheet Addon to be published for just of our domain (not public web). Individuals on my team have been able to do this successfully in the past but after 1/25/2019 when Google removed Add-Ons from Google Chrome Store we've been having difficulties.
I am trying to follow: https://developers.google.com/gsuite/add-ons/how-tos/publish-addons#publishing_instructions
But get the following error when trying to configure the G Suite Marketplace API:
Project Key is not associated with current project or the script version doesn't exist.
I am pulling the project Key from File --> Project Properties:
Does anyone have any idea where I am going wrong or know of good tutorial of how to publish a private Google Sheet Add-on?