database.default.dsn not working

hello, I am trying to connect to postresql using the dsn parameter for the default database schema
I have confirmed the pdo_pgsql is enabled in phpinfo, ultimately I need to be able to add sslverify to the dsn string to make an SSL only connection to the postgresql database
here is my dsn - no connection, does not work
database.default.dsn ='pgsql:host=xx.xx.xx.xx;port=5432;dbname=xx;username=xxx;password=xxxx;sslmode=verify-ca;sslrootcert=/ssl/db/server-ca.pem;sslcert=/ssl/db/client-cert.pem;sslkey=/ssl/db/client-key.pem'
#database.default.hostname = ip
#database.default.database = dbname
#database.default.username = dbuser
#database.default.password = dbpass
#database.default.DBDriver = Postgre
#database.default.port = 5432
#database.default.schema = public


if I un comment the below - this works
#database.default.dsn ='pgsql:host=xx.xx.xx.xx;port=5432;dbname=xx;username=xxx;password=xxxx'
database.default.hostname = ip
database.default.database = dbname
database.default.username = dbuser
database.default.password = dbpass
database.default.DBDriver = Postgre
database.default.port = 5432


I have been referencing the following database configuration page on codeigniter user guide
https://codeigniter.com/user_guide/datab...h-env-file
any help or guidance would be greatly appreciated