Cloud SQL is locked, it tells me to contact Admin to unlock.
I've created Cloud SQL instance with service account "appmaker-maestro@appspot.gserviceaccount.com" on IAM & ADMIN. But App Maker doesn't see it. Added some tables by dbForge - it didn't helped.
I already created connection before in another app, some month ago and it worked. But now it doesn't see SQL.
In order to configure Default Cloud SQL instance for App Maker you need to navigate to admin.google.com-> Apps -> Additional Google Services -> App Maker and setup database there. Here is a link to more detailed instructions: https://support.google.com/a/answer/7550053
You can also configure different CSQL instances for different departments within your organization.
来源：https://stackoverflow.com/questions/49763535/connection-from-app-maker-to-cloud-sql-is-locked