Error connecting with local Package registry

I am not able to connect Kibana with my locally deployed Elastic Package registry in an air gapped environment. I am getting this error in the kibana logs

error: RegistryConnectionError: Error connecting to package registry: request to https://<>:8443/search?type=content&kibana.version=9.2.1&spec.min=2.3&spec.max=3.5 failed, reason: unable to verify the first certificate