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: Put a tic on httpdocs and then click on Add to Archive
Step 3: Give a name of the archive file and click OK.
Step 4: After that click on the archive file and download it.