Unraid management access and acces to containers via SSL

I'm running an unraid server test environment. Now as a NextCloud docker container is working well since a while I would like to have secure access to the management of the server and the NextCloud container as well.
I just want to generate a certificate to have one for the server.
But I found no way to generate one yet...?

My domain is: I have a fixed external IP (V4) address on my router...

I ran this command: None

It produced this output: None

My web server is (include version): HP 83E7 Version KBC Version 07.D4.00

The operating system my web server runs on is (include version): Unraid OS 7.3.0

My hosting provider, if applicable, is: None

I can login to a root shell on my machine (yes or no, or I don't know): Yes
But configuration is done via Webgui...

I'm using a control panel to manage my site (no, or provide the name and version of the control panel): No

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot): Client? Unraid Server...

This is a question that's really better directed to Unraid. Let's Encrypt is an automated service that works through the use of client software; there's no web form that you can use to get a certificate or any such thing. I'd guess that Unraid either includes such a client or has one available, but once that's really a question for them.

Thank you for your reply.
I saw the possibility to activate SSL encryption by offering a certification file within the settings
of the server. So I thought I can create such a file via Let's Encrypt.
My thinking was too simply so it seems...
Now I'm going to contact the Unraid Community as suggested fro you.

That really isn't going to be compatible with how Let's Encrypt is designed. Most server software any more has a module, sometimes optional, to work directly with Let's Encrypt to obtain a certificate (and what you'd do in that case would be to click a button or something similar to do so), and also keep it renewed. I'm not familiar enough with Unraid to know if there's something similar available there, but if not, Let's Encrypt probably isn't going to be a good solution for you.

In Unraid OS you normally don’t manually generate one single certificate for everything on the server. The usual way people handle this is using a reverse proxy (like Nginx Proxy Manager or SWAG). You point a domain at your public IP, and then the proxy takes care of issuing a Let’s Encrypt SSL certificate for you.
After that, you just access everything through HTTPS:
Unraid web UI
Nextcloud container
any other Docker apps
You’ll also need to forward ports 80 and 443 on your router so the certificate can be issued properly. Trying to create and manage a certificate directly inside Unraid usually gets messy because each service (and container) handles SSL differently. The reverse proxy approach is just much cleaner and what most people end up using.

Good morning,
thanks for your reply. Reverse proxy sounds good, so I will move in that direction as soon as I can...