Error connecting to package registry

My Kibana is running behind corporate proxy, with curl, epr.elastic.co is reachable, but with Kibana service, I got below error, and added signer certificates into /etc/default/kibana
NODE_EXTRA_CA_CERTS="/etc/kibana/certs/live-kibana-bundle.pem" , and set http_proxy/https_proxy in /usr/lib/systemd/system/kibana.service, but no luck, the error is as below.

[ERROelease=true&kibana.version=8.11.3 failed, reason: getaddrinfo ENOTFOUND epr.elastic.coR][plugins.fleet] Failed to fetch latest version of synthetics from registry: Error connecting to package registry: request to https://epr.elastic.co/search?package=synthetics&prerelease=true&kibana.version=8.11.3 failed, reason: getaddrinfo ENOTFOUND epr.elastic.co

Thanks in advance.

Arthur

Fixed it by appending below line in /etc/kibana/kibana.yml, hope this helps others.
xpack.fleet.registryProxyUrl: http://proxy.csd.com:8888

@A_Niu Welcome to the community and Thanks for Providing the Solution to your Topic.
Nicely Done!