Use $USER@$OVPN_CN for OTP label.

bin/ovpn_otp_user

@@ -26,8 +26,8 @@ fi
 if [ "$2" == "interactive" ]; then
     # Authenticator will ask for other parameters. User can choose rate limit, token reuse policy and time window policy
     # Always use time base OTP otherwise storage for counters must be configured somewhere in volume
-    google-authenticator --time-based --force -l "${1}@OpenVPN" -s /etc/openvpn/otp/${1}.google_authenticator
+    google-authenticator --time-based --force -l "${1}@${OVPN_CN}" -s /etc/openvpn/otp/${1}.google_authenticator
 else
     google-authenticator --time-based --disallow-reuse --force --rate-limit=3 --rate-time=30 --window-size=3 \
-        -l "${1}@OpenVPN" -s /etc/openvpn/otp/${1}.google_authenticator
+        -l "${1}@${OVPN_CN}" -s /etc/openvpn/otp/${1}.google_authenticator
 fi