How to edit files with File Manager in Plesk
To edit files in File Manager, perform the following steps:
1 – Logged in to Plesk.
2 – Go to Websites & Domains.
3 – Click File Manager under the domain you want to manage it.
4 – Navigate to the folder where the file exists that you want to edit.
5 – Click Edit in Text Editor from the drop down icon.
6 – Make your changes and click Save.