Location of SSL Certificate and Key for HTTPS Communication

[j2cj2c]

Hello, a question regarding SSL and the Payer Server Test Suite.

I am running the DTR test kit locally using Docker.
When I run the payer server locally, the test suite behaved as expected. However, the moment I try to communicate with an actual payer server, which requires HTTPS communication, I run into this error:

1.03 Validate that the static response conforms to the DTR Questionnaire Package operation definition.
Error: SSL_connect returned=1 errno=0 peeraddr=XX.XXX.X.XXX:443 state=error: certificate verify failed (unable to get local issuer certificate)
/usr/local/bundle/gems/rest-client-2.1.0/lib/restclient/request.rb:776:in 'rescue in transmit'

In the Inferno guide, there is this documentation about SSL setup:
https://inferno-framework.github.io/docs/deployment/ssl.html

But I imagine the request is not coming out from the Nginx container.

Where should the SSL certificate and key be included so that I can send the $questionnaire-package request over HTTPS?