It's not obvious what and in which order should you do to get your add-on published.
Initially, I wrote this step-by-step guide for myself but I think it could be useful for many people.
- Create a project on script.google.com, develop your add-on and test it with "Test as add-on...". At this stage, any working code would be OK. An approval process is long enough to polish and test your code in parallel.
- Create a project in GCP console.
- Enable Gsuite Marketplace API in the API section of GCP.
- Get Project ID from GCP console (how to find)
- In your project on script.google.com use the menu: Resource / Cloud Platform project / Set id
- Publish / Deploy as add-on (select type & etc) / In Chrome Webstore developer console "Save draft". (You should have an account)
- Upload logo 96x96 and send it for verification. Any custom logo requires branding verification so you have to wait.
- OAuth verification will take some time. I will write another post about it. Check this out if you have problems.
- GSuite Marketplace API / Configuration / Upload icons, specify Script ID from App script, and Project ID / Save changes
- Make promo image and screenshots and publish to testers only in CWS.
- Wait for OAuth to be approved.
- In Chrome Webstore developer console make public your add-on public. (it's better to use the old version of developer console located on https://chrome.google.com/webstore/developer/dashboard)
- Wait for GSuite Marketplace add-on to be published.