diff --git a/Synology-NAS-Guide.md b/Synology-NAS-Guide.md
index f49cc90..a3e5064 100644
--- a/Synology-NAS-Guide.md
+++ b/Synology-NAS-Guide.md
@@ -45,7 +45,9 @@ Alternatively, you can change the certificates install path to your DSM cert lib
 For example:
  
     $ export CERT_FOLDER="$(find /usr/syno/etc/certificate/_archive/ -maxdepth 1 -mindepth 1 -type d)"
-    $ ./acme.sh  --issue -d YOURDOMAIN.TLD --dns dns_cf \
+    $ export CERT_DOMAIN="your-domain.tld"
+    $ export CERT_DNS="dns_cf"
+    $ ./acme.sh  --issue -d "$CERT_DOMAIN" --dns "$CERT_DNS" \
         --certpath "$CERT_FOLDER/cert.pem" \
         --keypath "$CERT_FOLDER/privkey.pem" \
         --fullchainpath "$CERT_FOLDER/fullchain.pem" \