You need to set up permissions for a set of Compute Engine instances to enable...

Create a service account with an access scope. Use the access scope ‘https://www.googleapis.com/auth/devstorage.write_only’.

Create a service account with an access scope. Use the access scope ‘https://www.googleapis.com/auth/cloud-platform’.

Create a service account and add it to the IAM role ‘storage.objectCreator’ for that bucket.

Create a service account and add it to the IAM role ‘storage.objectAdmin’ for that bucket.