SyncWith doesn't yet have the option to upload SSL certificates. However, in most cases you should be able to add the ?ssl-mode=no-verify string to your query to get things working.
The ssl-mode=no-verify setting requires using the Connection string mode to enter your login information; it is not compatible with the Connection parameters mode.
You can construct a connection string by filling in the necessary values in this template connection string: postgres://YourUserName:YourPassword@YourHostname:5432/YourDatabaseName