The default database user has dbo permission, if you want to have different mssql database user with different permissions, you can follow the steps below to create them.
1. Login to your Hosting Control Panel.
2. Click "Databases" from the top menu
3. Click "Extra DB users" and then click the blue "+" button to add new mysql user
4. In the pop up window, select the mysql database with you want to create additional database user for, then fill the new database user info, select the corresponding permission to create it