The page that explains how to stop the [TLS-SNI-01] it (How to stop using TLS-SNI-01 with Certbot) mentions this:
Ideally your web server should allow both ports. If that’s not possible, for instance because your ISP blocks port 80, you’ll need to switch to the dns-01 challenge, or use an ACME client that supports tls-alpn-01.
Unfortunately there is no link to a p[age that explains how to do this.
Steps taken: I changed port-forwarding of my router. It redirects external port 80 (and external port 443) to internal port 443. Unfortunately that does not work.
My domain is: https://blucap.no-ip.org
I ran this command:
sudo certbot renew --dry-run
It produced this output:
Timeout after connect (your server may be slow or overloaded) To fix these errors, please make sure that your domain name was entered correctly and the DNS A/AAAA record(s) … If you’re using the webroot plugin, you should also verify that you are serving files from the webroot path you provided.
My web server is (include version): Apache/2.4.7 (Ubuntu)
The operating system my web server runs on is (include version): Ubuntu trusty (14)
My hosting provider, if applicable, is: no-ip.org
I can login to a root shell on my machine (yes or no, or I don’t know): Yes
The version of my client is Certbot is version 28