I should have added that I am also using Pi-hole and Unbound. This seems to be the issue. I now added the following to my unbound.conf but it's still not working unfortunately. Where domain.duckdns.org is my domain by DuckDNS and the IP points to the Nginx Proxy Manager.
local-zone: "domain.duckdns.org." static
local-data: "domain.duckdns.org. IN A 192.168.178.123"
NPM should serve as both, but only issuing SSL certificates for my local network is the issue. Have you taken a look at the tutorial I've linked in the original post?
And what do you mean with the port I've exposed? Exposed where? NPM uses port 81.
So I've followed the tutorial, added a wildcard certificate and tried to add a proxy host using the DuckDNS domain to point to NPM itself. When I open the mydomain.duckdns.org I get an error that I can't connect to the site.
Besides that NPM is working and I easily set up my actual domain and it's resolving to devices in my home network. For example cloud.myactualdomain.com is resolving to my Nextcloud running on a Raspi with a local IP with a valid SSL certificate. So NPM and the WireGuard tunnel are generally working as intended.
On which system should I try the openssl command and what's the port?
It's not only software vendors but Wayland itself lacks some crucial features. For me it's auto-type and screen magnification - both are showstoppers for me.
"For many years, it [socialist Zionism] was the most significant tendency among Zionists and Zionist organizations, and was seen as the Zionist sector of the historic Jewish labour movements of Eastern Europe and Central Europe, eventually developing local units in most countries with sizable Jewish populations."
BackInTime or Borg
BackInTime should be easier to set up, Borg is more feature-rich and flexible. If you have any questions, feel free to ask. I use both for local and remote backup for years.
Safe/unsafe might be the wrong word, but rsync is resumable and also copies permissions for example. dd is more like the brute force method of data transfer.