Connections are stoder in string_connections/ folder.
Should be of the type:
If you have an ODBC created pointed to the database
DSN=<YOUR_ODBC_NAME>
If you had it installed, you can use it directly from the code creating the following string_connection.
DRIVER={ODBC Driver 13 for SQL Server};SERVER=<FQDN_OF_THE_SERVER>;DATABASE=<YOUR_DATABASE>;UID=<YOUR_USER>;PWD=<YOUR_PASSWORD>