Dynu DDNS ACME validating challenge error

[zet.john.doe]

Hi ,
I'm trying to setup letsencrypt ssl certificate for my homelab environment in PVE 8.4.1. I don't have public ip so I got dynu.com account and set homelab.pl DDNS service.
I used hints from this thread https://forum.proxmox.com/threads/dynu-ddns-acme-anyone.74792/ to configure acme dynu plugin in proxmox datacenter.
Then, in proxmox\certificates\ACME I added my domain.



When I try to order cert I get :

"Loading ACME account details
Placing ACME order
Order URL: https://acme-v02.api.letsencrypt.org/acme/order/2524841811/406051616261

Getting authorization details from 'https://acme-v02.api.letsencrypt.org/acme/authz/2524841811/552048320041'
The validation for homelab.pl is pending!
[Sun Jul 13 10:09:41 CEST 2025] Getting Dynu token.
[Sun Jul 13 10:09:42 CEST 2025] Getting https://api.dynu.com/v2/dns/getroot/homelab.pl
[Sun Jul 13 10:09:42 CEST 2025] Creating TXT record.
Add TXT record: _acme-challenge.homelab.pl
Sleeping 30 seconds to wait for TXT record propagation
Triggering validation
Sleeping for 5 seconds
[Sun Jul 13 10:10:19 CEST 2025] Getting Dynu token.
[Sun Jul 13 10:10:23 CEST 2025] Getting https://api.dynu.com/v2/dns/getroot/homelab.pl
[Sun Jul 13 10:10:24 CEST 2025] Checking for TXT record.
[Sun Jul 13 10:10:24 CEST 2025] Getting https://api.dynu.com/v2/dns/100380107/record
[Sun Jul 13 10:10:25 CEST 2025] Removing TXT record.
Remove TXT record: _acme-challenge.homelab.pl
TASK ERROR: validating challenge 'https://acme-v02.api.letsencrypt.org/acme/authz/2524841811/552048320041' failed - status: invalid"

For the short moment I can see a TXT record added to my ddns zone and soon afterwards it is deleted.
What am I doing wrong? Correct me if I'm missing the point, this type of validation doesn't require access to my server by letsencrypt, right?

 

[janus57]

Hi,

homelab.pl is registered since "2024-12-18", and it's DNS servers are hosted on cloudflare.

Are you sure you have correctly set up your domain (if you own it) ?

Best regards,

 

[zet.john.doe]

Hi,
Thanks for fast reply. Well, I don't have real domain bought. It's just a local domain created in my homelab. As a matter of fact I use self signed certificates but it doesn't work with Adguard Home. It requires real certificates to set up dns encryption like DoH and DoT. That' what I want to accomplish.
Summing up: if I choose a different dns name instead of homelab.pl which is not used by anybody , is there a chance to get a valid LetsEncrypt cert in the way I'm trying ?

Best regards,

 

[janus57]

Hi,

If I choose a different dns name instead of homelab.pl which is not used by anybody , is there a chance to get a valid LetsEncrypt cert in the way I'm trying ?

If you need a real TLS certificate with LE you need to own your domain, it's not possible to use the domain of another person or use one that is not registered.

Best regards,

 

[zet.john.doe]

Hi, thank you for clarification. I'll have to buy a valid domain name in that case and register it in Dynu DDNS.

Best regards,