Certificate error in logstash

I have configured elastic and logstash couple of years ago and now I am getting certificate expired error.
This is happening when logstash is trying to connect to elastic.

The error seen in logsatsh is as below :

[2024-12-09T20:14:45,228][INFO ][logstash.outputs.elasticsearch][main] Failed to perform request {:message=>"PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target", :exception=>Manticore::ClientProtocolException, :cause=>#<Java::JavaxNetSsl::SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target>}

I am using the self signed CA that has come along with the default installation.
Could you please let me know who do I renew the certificate which has expired ?