diff --git a/dnsapi.md b/dnsapi.md
index 89af481..792236e 100644
--- a/dnsapi.md
+++ b/dnsapi.md
@@ -2728,6 +2728,8 @@ Ok, let's issue a cert now:
 acme.sh --issue --dns dns_cpanel -d example.com -d www.example.com
 ```
 
+(see https://api.docs.cpanel.net/cpanel/introduction/#cpanel-or-webmail-session-url-1 regarding cPanel ports)
+
 The `cPanel_Username`, `cPanel_Apitoken` and `cPanel_Hostname` will be saved in `~/.acme.sh/account.conf` and will be reused when needed.
 
 Please report any issue to [https://github.com/acmesh-official/acme.sh/issues/3732](https://github.com/acmesh-official/acme.sh/issues/3732)