Steps to download website backup using Plesk
Step 1: At first login to the Plesk control panel and click on Website & Domains then select the domain for which you want to take the backup and then go to file manager.
Step 2: Select the folder (or several folders, if needed) using the checkbox and click Add to Archive. In this case, we selected only httpdocs and then click on Add to Archive.
Step 3: In the opened window, give your archive a name and press OK. The archive (.zip file) will be created in the same directory.
Step 4: Click on the button next to the created .zip file, and then click Download. The file will be downloaded to your PC.