I see the error
javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
This indicates the file
/app/.jdk/jre/lib/security/cacerts on your dyno does not have the necessary certificates need to trust a service you are invoking. You can customize this file by creating a
.jdk-overlay/jre/lib/security/cacerts file in your repo, as describe in this Customizing the JDK on Dev Center.
Very often you can use the
cacerts in your local JDK installation at