I change some settings to elastic-apm.
https://www.elastic.co/guide/en/apm/server/current/configuration-process.html
I want to verify if the setting is actually changed. but not sure how to check ..
Is there an endpoint where I can view the current configuration?
The only way to get configuration is to check apm-server.yml in your instance, but if you want to check your agent configuration you can use Agent Configuration API, for more information check https://www.elastic.co/guide/en/apm/server/current/agent-configuration-api.html.