Now that you have selected the ODBC Source you need to set the SQL Server within ExSync.
To do this, select the Database Management Tab as you did before:

Now select the SQL Server button.

Enter the Server Name and also the Database (Exch_65 if you followed the instructions setting up the SQL Database earlier).
It is recommended that Windows Authentication is used as this is more secure and doesn't require a username or password.

Once this is done click OK to save the setup. Before synchronising your data, please read our guide on Date Ranges and Exchequer versions.