oauth2_server_trust_file

Specifies the path to a file containing one or more PEM-encoded public certificates that can be used to validate the HTTPS server’s identity. If unspecified, the system trust is used.

oauth2_server_trust_file = pathname

This parameter is optional and is only relevant when the value of
oauth2_server_validation_key
is set to the URL of an HTTPS JWKS endpoint.