How can I access the ssl certificate of my asp.net core app

Dear All,

Please I built my web service with asp.net core 3.1. I am using a java application to connect to this web service. But I get this exception when I try to connect to the webservice application endpoint

sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested targetsun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Please how do I get to access the ssl certificate. Also do I need to generate a public key when connect with the web service. I want all connection to be powered over https.

Need your advice. Thanks.

Thanks alot.