To create a database user, perform the following steps:
1 - Logged in to Plesk, https://your domain name:8443.
2 - Go to Databases.
3 - Click User Management.
4 - Click Add Database User.
5 - Enter Database user name.
6 - Enter password and confirm.
7 - Select Database for this user, or Any for a universal database user.
8 - Click OK.