To upload a website from your computer to the Plesk server by using File Manager, follow these steps:

1. On your computer, add the folder containing your website’s files to an archive (right-click the folder and select Send To > Compressed (zipped) Folder) from the context menu.
2. In the Customer Panel, go to Files, click the httpdocs folder to open it, click Upload Files, select the archive file, and click Open.
3. Once the file has been uploaded, click the checkbox next to it and select the Extract Files option.

If you want to edit pages of your website, you can do it in File Manager. It provides an HTML editor that allows visual editing of HTML pages (without needing to manually type HTML tags).
To edit a file in the HTML editor, place the mouse pointer over the file, click to open the file’s context menu, and select Edit in HTML Editor.

You can also edit files in the File Manager’s text editor. To open a file in the text editor, click to open the file’s context menu, and select Edit in Text Editor.

If you have files or web pages that you want to make inaccessible on the Internet, change these files’ access permissions in File Manager.
To edit access permissions for a file or a directory, click to open the context menu, and select Change Permissions.