My domain is: nas.symonds.eu
I ran this command: No command, used the create a Let's Encrypt certificate tool on my Synology NAS, certificate is created for my old domain nas.symonds.de.
It produced this output: Invalid domain. Please make sure the domain can be resolved into a public IP address.
I can login to a root shell on my machine (yes or no, or I don't know): yes
I'm using a control panel to manage my site (no, or provide the name and version of the control panel): Synology DSM.
The nas.symonds.eu domain is resolvable:
stuart@Stuarts-Mac-mini ~ % nslookup nas.symonds.eu
Server: 192.168.188.1
Address: 192.168.188.1#53
Non-authoritative answer:
Name: nas.symonds.eu
Address: 94.209.154.9
stuart@Stuarts-Mac-mini ~ % whois nas.symonds.eu
% IANA WHOIS server
% for more information on IANA, visit http://www.iana.org
% This query returned 1 object
refer: whois.eu
domain: EU
organisation: EURid vzw/asbl
address: Telecomlaan 9
address: 1831 Diegem
address: Belgium
contact: administrative
name: Marc Van Wesemael
organisation: EURid vzw/asbl
address: Telecomlaan 9
address: 1831 Diegem
address: Belgium
phone: +32 2 401 27 50
fax-no: +32 2 401 27 51
e-mail: domain-admin@eurid.eu
contact: technical
name: Peter Janssen
organisation: EURid vzw/asbl
address: Telecomlaan 9
address: 1831 Diegem
address: Belgium
phone: +32 2 401 27 50
fax-no: +32 2 401 27 51
e-mail: domain-tech@eurid.eu
nserver: BE.DNS.EU 149.38.1.26 2001:978:2:1:0:0:93:2
nserver: SI.DNS.EU 193.2.221.60 2001:1470:8000:100:0:0:0:1
nserver: W.DNS.EU 194.0.25.28 2001:678:20:0:0:0:0:28
nserver: X.DNS.EU 185.151.141.1 2a02:568:fe00:0:0:0:0:6575
nserver: Y.DNS.EU 194.146.106.90 2001:67c:1010:23:0:0:0:53
ds-rdata: 59479 8 2 5DBAA81BC0BEFE921886D8DA28498D9FD441B457FB0E3642A0B2F9811C8E15E0
whois: whois.eu
status: ACTIVE
remarks: Registration information: http://www.eurid.eu
created: 2005-04-28
changed: 2021-08-10
source: IANA