Using Percona XtraBackup to backup Aiven MySQL database

I’ve recently found Aiven and have set up a few databases under their ‘free’ offer, everything is working okay, and I’ve connected a couple of websites to the server.

I can see that daily backups are being taken, and I understand that the ‘Fork & Restore’ options aren’t available for free, but I’d like to know if it is possible to use Percona XtraBackup to manually backup or restore data to an Aiven ‘free’ instance.

So far, my cmd line looks like this:
xtrabackup --backup --host=****.d.aivencloud.com --port=24501 --user=avnadmin --password=**** --target-dir=/var/backups/aiven-live

However, I get the following error message:
[ERROR] [MY-011825] [Xtrabackup] failed to execute query 'LOCK INSTANCE FOR BACKUP' : 1227 (42000) Access denied; you need (at least one of) the BACKUP_ADMIN privilege(s) for this operation

I did try spinning up a ‘full trial’ instance to see if it was a limitation of the free offer but received the same error.

Any help would be appreciated.