How do I choose a specific Server Certificate?

Hello,
I used the following commands to generate the Server Certificate:

# cp -r /usr/share/easy-rsa /etc/openvpn/
# cd /etc/openvpn/easy-rsa
# mv vars.example vars

# nano vars

export KEY_COUNTRY="US"
export KEY_PROVINCE="CA"
export KEY_CITY="NY"
export KEY_ORG="MyName"
export KEY_EMAIL="[email protected]"
export KEY_OU="OpenVPN"

# ./easyrsa init-pki
# ./easyrsa build-ca nopass
# ./easyrsa gen-req server nopass                        
# ./easyrsa sign-req server server
# ./easyrsa gen-dh
# openvpn --genkey secret ta.key

Then I edited the vars file with the new contents and issued the above commands to generate the new certificate. Then I created a directory for each certificate in the /etc/openvpn directory and moved the following files to the corresponding directory:

# cp ta.key /etc/openvpn/DIRECTORY_NAME
# cp pki/ca.crt /etc/openvpn/DIRECTORY_NAME
# cp pki/private/SERVER_NAME.key /etc/openvpn/DIRECTORY_NAME
# cp pki/issued/SERVER_NAME.crt /etc/openvpn/DIRECTORY_NAME
# cp pki/dh.pem /etc/openvpn/DIRECTORY_NAME

Now I want to generate keys for clients using the following commands:

# ./easyrsa gen-req client_name nopass
# ./easyrsa sign-req client client_name


How do I generate my client for a specific certificate?


Thank you.