How to use ${_self.CA_CERT} in when accessing Postgres DB from Nodejs app?

Goal is to avoid Error: self signed certificate in certificate chain or disabling it by setting Node env.

I do not think copying content from ${_self.CA_CERT} env to file and uploading it to repository and referring it as file approach sounds safe. There is support page describing saving it using script and referring it at runtime, I tried it like

DATABASE_URL=${self.DATABASE_URL}&sslrootcert=/workspace/ca_cert.cert

even tried setting NODE_EXTRA_CA_CERTS

I am using Postgraphile as middleware in my case, trying to connect to dev database.