diff --git a/dnsapi.md b/dnsapi.md
index ebe95b2..2fec42a 100644
--- a/dnsapi.md
+++ b/dnsapi.md
@@ -2819,6 +2819,25 @@ The credentials will be saved in `~/.acme.sh/account.conf` and will be reused wh
 Please report any issue to [https://github.com/acmesh-official/acme.sh/issues/3848](https://github.com/acmesh-official/acme.sh/issues/3848)
 
 
+## 140. Use s-dns.de API
+
+First generate your dns zone key. Open your existing nameserver entry, click on [Passwort für dynamic DNS generieren] and save your zone. This generates a new key for your zone. 
+
+```sh
+export SDNS_ZONE_KEY="Key"
+```
+
+Ok, let's issue a cert now:
+```sh
+acme.sh --issue --dns dns_sdns --domain example.com
+```
+
+S-dns nameservers use anycast. It is therefore possible that the server next to your location already provides the new record, while the CA reaches another one that does not have the TXT record yet. To avoid such timing errors the dnssleep flag can be set to a value of 240 seconds.
+
+```sh
+acme.sh --issue --dns dns_sdns --domain example.com --dnssleep 240
+```
+
 
 # ##################
 # Use custom API