How do I automate lets encrypt certificate

Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.

My domain is:iarch.duckdns.org

I ran this command:
sudo ufw allow 80,443/tcp
sudo nextcloud.enable-https lets-encrypt

It produced this output:

My web server is (include version):

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

My hosting provider, if applicable, is:

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):no

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you’re using Certbot):

this sounds interesting:

sudo journalctl -u snap.nextcloud.renew-certs.service

maybe go for

sudo systemctl status snap.nextcloud.renew-certs.service

too.