How to restore percona database from kubernetes? I got the backup works by setting these on the helm chart values (it works according to the documentation):
    google-cloud-storage-s3:
      type: s3
      s3:
        bucket: gcp_bucket
        credentialsSecret: google-cloud-storage-s3-backup
        region: us-west2
        endpointUrl: https://storage.googleapis.com/

It's uploaded successfully on the google cloud storage:

Then I tried to restore the backup:
gsutil -m cp -r \                                      
  &quot;gs://gcp_bucket/percona-2021-05-06-00:00:11-full.md5&quot; \
  &quot;gs://gcp_backup/percona-2021-05-06-00:00:11-full.sst_info/&quot; \
  &quot;gs://gcp_backup/percona-2021-05-06-00:00:11-full/&quot; \
  .
| [1.1k/1.1k files][  2.7 GiB/  2.7 GiB] 100% Done 942.3 KiB/s ETA 00:00:00     
Operation completed over 1.1k objects/2.7 GiB. 

sudo apt install percona-server-server percona-xtrabackup-80

The documentation said:
service mysqld stop
rm -rf /var/lib/mysql/*
cat xtrabackup.stream | xbstream -x -C /var/lib/mysql # --&gt; where is this from?
xtrabackup --prepare --target-dir=/var/lib/mysql 
chown -R mysql:mysql /var/lib/mysql
service mysqld start

The problem is, I could not find any file named copy-backup.sh or xtrabackup.stream in the backup directories, is there other way to restore the backup, also all files compressed with lz4?
The copy-backup.sh can be found on the repo
Then following the commands on the documentation will produce xtrabackup.stream file.