To protect a directory with a password, perform the following steps:
1 – Logged in to Plesk.
2 – Go to Websites & Domains.
3 – Click Password-Protected Directories.
4 – Click Add Protected Directory.
5 – Type in the path to the directory you want to protect (relative to the domain’s document root directory) and, optionally, a title that will be displayed to visitors.
6 – Click OK.