In your hosting account, you can create the necessary MySQL or MS SQL databases for your websites.

In Parallels Plesk Panel, create the databases and then the new associated users or grant access to existing users.

Log in to your Account Manager.
Click Web Hosting.
Click the Manage option displayed next to the hosting account you want to use.
Go to the Web Sites and Domains tab.
Click Databases.
Click Add New Database.
Fill in the Database Name and Type fields and click OK.
Select Create a new database user if you want to create a new user for this database and enter an associated user name and password. Otherwise, uncheck the option.
Click OK.
To allow other users to access your databases, select the Users tab and click Create New Database User.

NOTE – Each database user can access only one database type. However, you can create multiple users by reusing the same name for each database type.