Hi Im using opensearch 2.10.0 , running as a kubernetes pod with default (demo) certificates for opensearchm, but not sure how to change the password for admin user.
OpenSearch/OpenDistro are AWS run products and differ from the original Elasticsearch and Kibana products that Elastic builds and maintains. You may need to contact them directly for further assistance. See What is OpenSearch and the OpenSearch Dashboard? | Elastic for more details.
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As you will have seen from the automated message, OpenSearch is not an Elastic product. This forum is for help with Elasticsearch.
Have you asked your question in the OpenSearch forums? That is the best place to get help with OpenSearch.
Hope that helps!
Did you look at Cloud by Elastic, also available if needed from AWS Marketplace, Azure Marketplace and Google Cloud Marketplace?
Cloud by elastic is one way to have access to all features, all managed by us. Think about what is there yet like Vector Search, Security, Monitoring, Reporting, ES|QL, Canvas, Maps UI, Alerting and built-in solutions named Observability, Security and what is coming next 
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