After sign-in, every drive on the account is listed. A drive owner connects through the S3 gateway. The access key, secret, and bucket are already on the storage account. That includes the free 1 GB plan.
A team member does not receive S3 keys. A drive they can write to is backed up over WebDAV. Passwords and S3 secrets stay in memory for the backup that needs them.
Questions
Does the free plan use S3?
Yes. Drive owners, including the free 1 GB plan, sync through the S3 gateway.
How does a team member connect?
A team member who can write to the drive backs up over WebDAV. They do not receive S3 keys.