The configuration above seems incorrect. The options you should configure are called
output.elasticsearch.ssl.certificate_authorities: ["/etc/pki/root/ca.pem"]
output.elasticsearch.ssl.verification_mode: none
So in your config, it would look like this:
output.elasticsearch:
hosts: ["10.194.11.67:9200"]
protocol: "https"
username: "elastic"
password: "password"
ssl.certificate_authorities: [ "/etc/filebeat/elasticsearch-ca.pem" ]
ssl.verification_mode: none