FAQ: How do I fix “curl_exec: Peer’s Certificate issuer is not recognized… Hostname requested was: plugins.matomo.org”
…a folder on your server such as /path/to/your/cacert.pem add custom_cacert_pem = “/path/to/your/cacert.pem” to the [General] section of your config file config/config.ini.php. Make sure the certification is readable by your webserver….