I was just able to accomplish this.
Assuming that you have the hostname, database name and port set properly with credentials entered.
2 methods worked for me in the JDBC Parameters.
The one I use: ssl = true sslrootcert = D:<path to pem file>
I guessed to get this to work. I used my python knowledge for the proper parameter to use. Case matters.
The other one that worked: ssl = true sslfactory = org.postgresql.ssl.NonValidatingFactory
If the latter does not work, I’d guess that you, likely, don’t have the proper DB packages installed.