Create a reliable backup routine in Plesk: schedule backups, keep multiple restore points, and store copies off‑server using remote FTP storage.
Use Plesk Backup Manager to back up your website, databases and mail, download backups and restore them when needed.
If you need a quick backup (or Backup Manager is not available), you can back up your website manually: download the site files from httpdocs and export the database via phpMyAdmin. This guide explains the full process.