HikariCP Postgresql Driver Claims to not accept JDBC URL

There are a few issues with that URL and a latest PSQL driver may complain.

1. jdbc:postgres: should be replaced with jdbc:postgresql:
2. Do not use jdbc:postgresql://<username>:<passwor>..., user parameters instead: jdbc:postgresql://<host>:<port>/<dbname>?user=<username>&password=<password>
3. In some cases you have to force SSL connection by adding sslmode=require parameter

So your URL should be:

jdbc:postgresql://@pellefant.db.elephantsql.com:5432/cwkqmdql?user=cwkqmdql&password=SsVqwdLxQObgaJAYu68O-8gTY1VmS9LX

or

jdbc:postgresql://@pellefant.db.elephantsql.com:5432/cwkqmdql?user=cwkqmdql&password=SsVqwdLxQObgaJAYu68O-8gTY1VmS9LX&sslmode=require

I hope that will help.