openvpn client connect to remote freebsd server

[yhq_34]

I setup openvpn client connect remote freebsd server. but failed below was log,

I copied the ca and client cert key to opnsense trust.
what's the problem?

2020-08-05T15:32:38
openvpn[76633]: OpenSSL: error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed
2020-08-05T15:32:38
openvpn[76633]: VERIFY ERROR: depth=1, error=self signed certificate in certificate chain: CN=FOCUS CA