All Windows Hosting customers benefit from Microsoft SQL Server database support. To configure your ASP.NET application to access your database you will need to set a connection string within your ASP.NET application’s Web.Config file. Below is a sample ASP.NET connection string which you can use to connect to your Microsoft SQL Server database:
<add name="SqlConnectionString" connectionString="Data Source=localhost\MSSQLSERVER2016;Initial Catalog=username_dbname;User Id=dbusername;Password=dbpassword;" providerName="System.Data.SqlClient" />
Remember to replace username_dbname as the database name you created in Plesk, along with the database username and password.