Review these points and make any needed adjustments to your SQL database settings before installing and configuring the Engine:
The SQL Server service must be listening via TCP/IP v4, because the Engine requires TCP/IP via port number for access.
Some editions of SQL Server do not have TCP/IP enabled by default. If there are multiple instances, the instance that you just installed and configured might not be listening on the default port of 1433.
Firewall rules might need to be modified.