You can follow below steps to set the default Plesk page:
- Login to Plesk.
- Click on “Websites & Domains” and then click on “Virtual Directories”.
- After that choose “Directory Properties” to add default page.
- Here you will find “Use Default documents” checkbox, just select this and add default documents which you want to add.
- You can use “Up” button to take your page on top of the list and after that click on Ok button.