When WordPress instance is deployed via WP Toolkit in Plesk, database name and database username are set automatically.
How to define such settings manually?
How to select version of WordPress before the installation?
2 options are available:
Using WP Toolkit.
Go to Domains > example.com > Install WordPress or Domains > example.com > WordPress > Install and set the required settings (options under Database and Automatic Update Settings are hidden by default, so unfold these options if necessary):
From the application catalog.
Go to Domains > example.com > Applications > Featured applications > WordPress > click drop-down on Install > Install (Custom):