How to use DNS through VPN?

Question

Domain Name System

There are 2 cars.
The first is the openvpn server and dns server, the second is the client. I can't use 10.8.0.1 as a DNS as a client because it doesn't work.
1st

• External ip - 1.1.1.1
  
• Local ip - 192.168.199.2
  
• OpenVPN ip - 10.8.0.1
  

2nd

• External ip - 2.2.2.2
  
• Local ip - 192.168.1.2
  
• OpenVPN ip - 10.8.0.2
  

Machines are pinged OpenVPN
server config

dev tun
proto tcp
port 12345
ca ca.crt
cert server.crt
key server.key 
dh dh1024.pem
topology subnet
server 10.8.0.0 255.255.255.0
cipher AES-128-CBC
comp-lzo
mssfix
keepalive 10 120
verb 3

Client config

client
dev tun
proto tcp
remote 1.1.1.1 12345
ca ca.crt
cert sixth.crt
key sixth.key
cipher AES-128-CBC
nobind
comp-lzo
persist-key
persist-tun
verb 3