I have created a Google Cloud Project MySQL database to use in conjunction with the Jdbc service provided by Google Apps Script. Everything went as planned with the connecti
I am not sure whether this question has been resolved or not, but let me add this answer.
I also faced the same problem but I found the resolution. What I did is:
First, go to the console.
https://console.cloud.google.com
Then, open IAM. and add the account as a member and add this permission: "Cloud SQL Client".